It’s understandably challenging (and worrying) to determine which COVID-19 vaccine is the most promising, especially with databases of detailed information to analyze.
Each day, our social media apps and news programs display headlines such as these; “Which COVID-19 vaccine is the most effective? Moderna vs. Pfizer, which is better? Are COVID-19 vaccines safe? What should I do after getting vaccinated?” It’s not shocking to see why.
You might be keen on getting the vaccine to protect yourself and your loved ones, but most of us likely have some form of doubt, fear, or anxiousness about getting the shot.
Unsurprisingly, most of the doubts and queries stem from this fact; It typically takes 10-15 years to develop a vaccine. The COVID-19 vaccine has only taken less than a year to be manufactured, trialed, and approved. Because of this, you might be concerned about the safety and possibility of long-term side effects from the COVID-19 vaccine.
With three different vaccines approved for use in the U.S. (and more coming), you will need to understand more about the COVID-19 vaccination. So, let’s dive into understanding the various types of vaccines available, including three vaccines currently approved for use out of the U.S.! A COVID-19 comparison chart further down this article will give you quick and compact information.
The Three Vaccines Authorized by the FDA.
So far, three vaccines in the United States have attained the green light. Firstly, the vaccine developed via the partnership between Pfizer and German-manufacturer BioNTech (Pfizer-BioNTech), followed by the vaccine by Moderna, which was created with assistance from the National Institute of Allergy and Infectious Diseases.
Janssen Pharmaceuticals, the vaccine division of Johnson & Johnson, synthesized the latest one and managed to garner approval for its unique one-shot vaccine.
Vaccine Types
Here’s the fundamental difference between the vaccines. Pfizer’s and Moderna’s are mRNA vaccines, whereas Johnson & Johnson’s (Jansen) is an adenovirus-based vaccine.
You might ask, what’s the difference?
Firstly, manufacturers formed the mRNA vaccine utilizing an extremely new technology. No vaccination before the COVID-19 was mRNA-based. Unlike some vaccines, these mRNA-based ones require two shots instead of one to attain sufficient efficacy. [1]
On the other hand, J&J/Janssen COVID-19 vaccines require only one shot. You will no longer need to wait for your second shot to boost efficacy. After your first shot (and a period of about 2 weeks), your body should produce enough antibodies to reduce the symptom severity and chances of infection if you ever come into contact with the COVID-19 virus. [1]
Secondly, mRNA vaccines are less stable. Pfizer’s vaccine requires strict storage instructions to prevent damage to the vaccine. It can last up to 6 months in a specialty freezer and must be stored at minus 70 degrees Celsius! [2] That’s really cold!
Moderna claims that their vaccine will last up to 6 months at roughly minus 20 degrees Celsius. [2] An unpunctured vial can last 30 days at temperatures between 2°C and 8°C. [3]
In contrast, the adenovirus vaccine is more stable than mRNA-based ones and can be stored between 2°C to 8°C until its expiration date, which is months! [4]
Finally, the way they function varies depending on the type. mRNA vaccines utilize strands of genes. However, they do not alter your DNA in any way! They teach your body to synthesize a particular protein that triggers an immune reaction to ultimately give you some form of protection against the COVID-19 virus. [5]
The adenovirus-based vaccine works in a varying way. Take this analogy of the Trojan horse. Your body accepts this harmless virus, but instead of releasing something harmful like hidden soldiers, it releases a gene that codes for the spike protein. This spike protein, in turn, will trigger a reaction by the immune system, causing your body to form antibodies as a response. [6]
This is how your body learns how to defend against the COVID-19 virus if ever you come into contact with it!
| Pfizer | Moderna | J&J/Janssen | |
| Type | mRNA-based | mRNA-based | Adenovirus-based |
| Shots required | Two | Two | One |
| Stability (and storage requirements) | Least stable, stored at very cold temperatures | Moderately stable, lasts 30 days at 2-8 degrees Celsius. | Most stable, can last months at 2-8 degrees Celsius. |
| Method of inducing protection | mRNA acts as instructions to teach your cells how to manufacture the spike protein | mRNA acts as instructions to teach your cells how to manufacture the spike protein | A harmless virus (not the COVID-19 virus) is utilized. |
Breakdown of The Different Brands
Pfizer-BioNTech
Who Should Be Given This Vaccine?
Anyone aged 12 and older can be recommended this vaccine, including those with diabetes, kidney disease, and pulmonary disease. [7, 8] Pregnant women are vaccinated only if the benefits of getting the vaccine outweigh the risk [9].
Who Should NOT Be Given This Vaccine?
Those who have experienced immediate allergic reactions (within 4 hours of getting the vaccine) or very severe allergic reactions such as difficulty breathing or anaphylaxis after receiving the first shot should not receive the second.
Those with known immediate or severe allergies to ingredients inside the vaccine, such as polyethylene glycol, should not receive any immunization shots. [7]
How Effective Is It?
From clinical trials, this vaccine achieved an efficacy percentage of 95 (95%) in people who had received both doses and had no evidence of previous infection by COVID-19. [7]
What Is the Dosing Schedule?
You will be given two doses three weeks (21 days) apart. [7]
Are There Any Possibilities of Side Effects?
You may experience redness, swelling, or soreness at the injection site. Common side effects include headache, fever, muscle ache, fatigue, chills, and nausea. These side effects occur more commonly after the second dose is administered. [7]
Most of the side effects are minimal or moderate and last a few days, but a small handful experience side effects with high severity and require more extended bed rest. [7]
In clinical trials, highly severe adverse effects like death or organ damage were almost equal between the placebo group (those who did not get the vaccine) and the vaccinated group, and only two cases were considered as possibly associated with the vaccine. [10] In short, data suggests that those who do not get the vaccine are more likely to experience negative consequences than those who received the vaccine. [7]
What Do Recipients Need to Know?
Before you get your shot, tell your vaccinator if:-
- You are ill
- You have any allergies or a fever
- You are on any medications, including blood thinners
- You have any medical conditions or are immunocompromised
- You are pregnant or breastfeeding or intend to get pregnant
- You have received another COVID-19 injection [11]
Moderna
Who Should Be Given This Vaccine?
Anyone aged 18 and older can be recommended this vaccine. [12] Pregnant women are vaccinated if the benefits of getting the vaccine outweigh the risk [13].
Who Should NOT be Given This Vaccine?
Those who have experienced immediate allergic reactions or very severe allergic reactions such as difficulty breathing or anaphylaxis after receiving the first shot should not get the second. [12]
Those with known immediate or severe allergies to ingredients inside the vaccine, such as polyethylene glycol, should not receive any immunization shots. [12]
How Effective Is It?
From clinical trials, this vaccine achieved an efficacy percentage of 94.1 (94.1%) in people who got both shots and had no evidence of any previous infection by COVID-19. [12]
What Is the Dosing Schedule?
You will be given two doses four weeks (28 days) apart. [12]
Are there Any Possibilities of Side Effects?
You may experience redness, swelling, or soreness at the injection site. Common side effects include headache, fever, muscle ache, fatigue, chills, and nausea. These side effects occur more commonly after the second dose is administered. [12]
Most side effects are minimal or moderate, but a small handful experience side effects with high severity and require more extended bed rest. [12]
Anaphylaxis is a life-threatening condition that causes rashes, low pulse, and shock. It is a rare event after the receipt of the Moderna COVID-19 vaccine; About 2.5 cases per million Moderna COVID-19 vaccines administered. There are no anaphylaxis-related deaths reports thus far. [13]
What Do Recipients Need to Know?
Before you get your shot, tell your vaccinator if:-
- You are ill
- You have any allergies or a fever
- You are on any medications, including blood thinners
- You have any medical conditions or are immunocompromised
- You are pregnant or breastfeeding or intend to get pregnant
- You have received another COVID-19 injection [14]
Johnson & Johnson (Jansen)
Who should Be Given This Vaccine?
Anyone aged 18 and older can be recommended this vaccine. [15] Pregnant women are vaccinated if the benefits of getting the vaccine outweigh the risk [13].
Who Should NOT Be Given This Vaccine?
Those with known immediate or severe allergies to ingredients inside the vaccine should not be given any vaccine shots. [16]
How Effective Is It?
This vaccine achieved an efficacy percentage of 66.3 (66.3%) two weeks after receiving their single shot from clinical trials. This is in people who had no evidence of previous infection by COVID-19. [15]
What Is the Dosing Schedule?
You will receive one dose. [15]
Are There Any Possibilities of Side Effects?
You may experience redness, swelling, or soreness at the injection site. Common side effects include headache, fever, muscle ache, fatigue, chills, and nausea. These side effects are more common in those 18-59 years of age. [15]
Most side effects are minimal or moderate, but a small handful experience side effects with high severity and require more extended bed rest. [15]
In clinical trials, severe adverse effects were reported by 0.4% of the participants in the vaccinated group and 0.4% of the participants in the placebo group. The U.S. Food and Drug Administration (FDA) classified three of those severe adverse event cases as likely to be caused by the vaccine. [16]
What Do Recipients Need to Know?
Before you get your shot, tell your vaccinator if:
- You are ill
- You have any allergies or a fever
- You are on any medications, including blood thinners
- You have any medical conditions or are immunocompromised
- You are pregnant or breastfeeding or intend to get pregnant
- You have received another COVID-19 injection [17]
Comparison Chart
| Pfizer | Moderna | Johnson & Johnson (Jansen) | |
| Minimum age required | 12 | 18 | 18 |
| Number of shots | Two | Two | One |
| Days between shots | 21 | 28 | Inapplicable |
| Efficacy percentage (based on clinical trials) | 95 | 94.1 | 66.3 |
| Most commonly reported side effect | Local: Pain at injection site Systemic: Fatigue, headache, and new or worsened muscle pain | Local: Pain at injection site Systemic: Fatigue, headache, and myalgia (pain in muscles) | Local: Pain at injection site Systemic: Fatigue and headache |
| Occurrence of severe adverse event (based on clinical trial) | 0.6% (almost equal to placebo group). FDA only considered 2 of those cases as possibly associated with the vaccine: 1 case of shoulder injury and 1 case of lymphadenopathy | 1% (equal to the placebo group). FDA only considered 3 of those cases as possibly associated with the vaccine: 1 case of hard-to-control nausea and vomiting, and 2 cases of facial swelling (in people who had previous cosmetic procedure) | 0.4% (equal to the placebo group). FDA only considered 3 of those cases as possibly associated with the vaccine: 1 case of hypersensitivity reaction, 1 case of pain at the injection site (thought to be related to brachial neuritis), 1 case of systemic reactogenicity |
What Does the Efficacy Rate Mean?
This is an essential piece of information. Many people choose the ‘best’ vaccine based on this single piece of information. For example, Pfizer’s and Moderna’s vaccines have an efficacy rate of over 90%, while the Johnson & Johnson (Jansen) vaccine has an efficacy rate of 66.3%
Understandably, you might think that the Pfizer or Moderna vaccine is better because its efficacy rate is higher. Is this the case, though?
Firstly, you must comprehend what this efficacy rate refers to. Vaccine efficacy is how much a vaccine will reduce diseases in a group of participants in a clinical trial.
The vaccine efficacy percentage does NOT dictate how well this vaccine will work for people outside of these clinical trials and in real-life scenarios. There are so many factors that affect this effectiveness. This includes the health of the population and the type of variant of the Covid-19 virus.
Let’s compare the timeline of when these vaccine trials. The Pfizer and Moderna vaccines were tested in certain locations and at a time with fewer variants of the Covid-19 virus. On the other hand, the Jassen vaccine was clinically trialed in different countries, such as South Africa. During this phase, there were variants of the virus present. Hence, it was tested in a population possibly exposed to both the original and variant versions of the virus.
Yet, it managed to reduce disease percentage to an impressive degree.
If you want to compare these vaccines head to head in efficacy, they would have to be tested in the same country, timeframe, and population, and for the same duration. Hence, the currently proposed efficacy rate of the vaccine doesn’t accurately determine how effective it would be in real-world scenarios or for your individual case.
The Possibility of Booster Shots.
Just like any other vaccine, the COVID-19 vaccines likely require booster shots. There has been no confirmation about this just yet, but Pfizer’s CEO suggests that annual vaccination may be necessary moving forward.
If we’ve learned how to live with the influenza virus, we will learn how to adapt to living with the COVID-19 virus as well, and this may include yearly revaccinations.
Vaccines Not (yet) Available in The U.S.
Oxford University and AstraZeneca developed one of the vaccines not yet made available in the U.S. This vaccination was first administered outside of a clinical trial on the 4th of January. Thus far, over 100 countries have approved its use. [18]
Sinovac, a Chinese biopharmaceutical company based in Haidian District in China, specializes in researching, developing, manufacturing, and developing vaccines for infectious diseases in humans. They have also released a vaccine. This vaccine is currently approved in 25 countries, including Malaysia, Thailand, Mexico, Pakistan, Hong Kong, and China. [18]
The next vaccine is approved for use in over 60 countries! Gamaleya Research Institute of Epidemiology and Microbiology in Russia developed the Sputnik V vaccine. It has undergone all three trial phases in Russia, but phases 2 and 3 were also performed in other countries such as India and Belarus. [18]
If you thought that was all, you’re entirely wrong. There are currently 119 vaccine candidates to date, and probably more to come! Over 330 trials were conducted in numerous countries. As a result, 15 vaccines have already been approved for use in at least one country. [18]
If you’re wondering which vaccine has the most countries that have approved it for public use, that’s the Oxford/AstraZeneca vaccine, also known as Vaxzevria! [18]
We’ll discuss a few vaccines that have been approved in other countries, but not the U.S.
Oxford/AstraZeneca
This viral vector-based vaccine uses similar technology to the single-shot Johnson & Johnson (Jansen) vaccine, which utilizes a harmless chimpanzee adenovirus to release a code for the spike protein upon entry into the body. [19]
Similar to the Moderna and Johnson & Johnson (Jansen) vaccine, this vaccine is only currently approved for use in those above 18 years of age. You will get two doses with 8 to 12 weeks in between. [20]
Its efficacy ranges due to different rates reported by clinical trials, but it is around 63-76% effective against symptomatic COVID-19. Different sources report different efficacy percentages. Interestingly, the efficacy is higher when the dosing interval is 12 weeks compared to 8 weeks. [20, 39]
The most common side effects for this vaccine are similar to the above-discussed vaccines; headache, fatigue, and muscle and joint pain. [21]
Currently, there’s a massive concern about whether or not this vaccine can cause a more severe side effect, which is blood clotting. In the European Economic Area, 30 blood clots or thromboembolic cases were reported after administration to roughly 5 million people as of March 10, 2021. A single case of fatality occurred in Denmark. [22]
Let’s put that into perspective. According to those numbers, the incidence of blood clots post-vaccination is roughly 0.000006%.
The EMA’s safety committee later decided that unusual blood clotting with low platelet count should be listed as a scarce side effect of this vaccine. COVID-19 itself can cause blood clots and fatality. Hence, they confirmed that the benefits of the vaccine continue to outweigh the risk of adverse effects. [23]
CoronaVac (Sinovac)
The CoronaVac also utilizes a virus to code for the spike protein, but unlike the other few we have explored, it does not use the adenovirus. Instead, it utilizes inactivated particles of the SARS-CoV-2 virus. This virus particle cannot replicate in your body and cannot cause COVID-19. [24]
Inactivated vaccines are synthesized using heat, radiation, or chemicals to modify the virus or particles of the virus, so that it does not cause the infection. [24]
In the body, these inactivated viral particles can produce substantial immune reactions to protect against future infections. [24]
Varying efficacy rates were reported from different trials in various countries, but it is around 50.4-65% effective. [25, 40] Like the AstraZeneca vaccine, the rates reported vary based on the location of the clinical trial. Unlike all the other vaccines though, the side effects were observed more frequently after the first dose. [26]
Sputnik V
This vaccine also utilizes adenovirus-based technology. Intriguingly, the adenovirus type is different for the doses. The first dose administered uses type-26 (Ad26), then the second booster dose utilizes type-5 (Ad5).
Currently, it stands as one of the three vaccines in the entire world that have achieved an efficacy rate higher than 90%. The vaccine’s efficacy was confirmed at 91.6% according to the data from 19,866 participants. [27]
The approved dosing regimen is two doses given 21 days apart, but recent studies have suggested that the doses can be given up to 3 months apart! [27, 28]
The most common side effects reported are flu-like symptoms, headache, injection site reaction, and fatigue.
45 out of 16,427 participants in a trial reported severe side effects in terms. Still, the independent monitoring data committee has ruled out these cases as caused by the vaccine itself. [29]
Bottomline: Which Is The Best COVID 19 Vaccine?
The bottom line is this: Each vaccine has its own risks and benefits. There is no such thing as the ‘best’ vaccine.
Take note that one factor, say the efficacy percentage, cannot singlehandedly determine the best vaccine for you. Each vaccine was tested and trialed in different countries at dissimilar timeframes in non-identical people with varying demographics, health attributes, and environments.
CDC and many other health organizations worldwide have declared that the benefits of getting the COVID-19 vaccine outweigh the risks.
However, if you’re worried about getting the vaccine, reach out to a healthcare provider you trust. Amidst all the chaos and uncertainty now, find someone who is qualified to give you health advice so you can get your questions answered and thoughts clarified.
Every individual plays a critical role in curbing the spread of this virus, whether they have received the vaccine or not. Let’s all take responsibility and work together in slowing and hopefully ceasing the spread of this virus. It has robbed us of enough precious resources, time, and lives.
FAQs for COVID-19 Vaccine Analysis
Can I get Covid after being fully vaccinated?
Yes, there is still a risk of being infected with COVID-19 post-vaccination, even if you have already completed the entire regimen. Hence, to safeguard yourself and the community, do not become complacent with the standard operating procedures (SOP) set by your government. [30]
Getting the vaccine doesn’t completely diminish the risk of getting COVID-19 or transmitting the virus. Still, it does help with reducing symptoms severity and preventing severe symptoms (such as breathing difficulty that requires ventilator use). It will also reduce the chances of you contracting the virus upon exposure. [30, 31]
If you have received the vaccine, you must still isolate yourself immediately if you experience any symptoms suggestive of COVID-19 infection. [30]
Is it safe to get the COVID-19 vaccine?
Yes, it is generally safe. All the currently authorized and approved vaccines have undergone rigorous testing to ensure safe public administration. The CDC and FDA continue to monitor the situation warily to make sure that there are no severe problems that arise. [32]
Widespread vaccination is the best strategy to create herd immunity and cease the spread of the virus. Getting the vaccine does not only protect you; it protects those who are unable to get the vaccine themselves due to their age or condition.
However, certain people should not get vaccinated. For example, those who have known severe allergies to any of the ingredients in the vaccine should not get the vaccine.
What is the effectiveness of the Moderna COVID-19 vaccine?
The efficacy is currently agreed as 94.1% in preventing laboratory-confirmed COVID-19 in individuals who have received the full regimen (two doses) and had no previous history of being infected with the COVID-19 virus. [12]
Has there been any side effects from the Covid vaccine?
This depends solely on the individual. The most common side effects reported are mild to moderate, and include headache, fever, fatigue, and muscle soreness. Generally, these side effects will resolve and subside within 1-2 days and will not lead to any permanent debilitation or harm. [33]
What are the chances of getting Covid-19 after the vaccine?
It depends on the vaccine you have received, plus, everyone reacts differently to each vaccine. Approved vaccines are up to 96% effective, so roughly 1 in 20 people who have completed their full vaccination regimen could still be infected with COVID-19 if exposed to the virus. [34]
Is the COVID-19 vaccine mandatory for anyone?
It is completely voluntary, and you are free to decide if you want to get the COVID-19 vaccine. [35] The best way to make this decision is to consult your doctor or reliable and credible sources. It is best not to base your decision solely on what social media or your friends tell you.
Some people cannot get the vaccine, such as those who are below the minimum approved age.
Are masks effective against the coronavirus disease?
Currently, masks are one of the most valuable resources widely available and effective in mitigating the spread of COVID-19. This efficacy of masks in stopping the spread of COVID-19 depends on the type of mask used, and how the user is wearing it. [36]
Stick to minimally 3-ply masks, and do not leave them hanging below your nose. [36]
Am I immune to COVID-19 after recovery?
The short answer is this; No one knows for sure. Some evidence suggests that those who have been infected garner at least 90 days of immunity from the COVID-19 virus following initial diagnosis and laboratory confirmation. [37]
However, don’t neglect SOPs set by your government or reject the vaccine if you have recently recovered from COVID-19. Immunity is not guaranteed or experts don’t know how long the immunity lasts after recovery.
How long am I contagious with COVID-19?
It depends on your own body. Adults with more severe or extremely critical illness, or who are immunocompromised will likely be infectious no longer than 20 days after onset of symptoms. There have been some rare reports of people shedding forms of the virus that could still replicate in another host beyond the 20-day mark. This is likely due to severe immunocompromise. [38]
Disclaimer: This article is only a guide. It does not replace the advice given by your own healthcare professional. Before making any health-related decision, consult your healthcare professional. We provide information based on the sources available at the date of publishing. Some of the information may be outdated or no longer applicable.
