Frequently Asked Questions About COVID-19 Vaccines

Author: Ivana Mišová, PhD.

Published at: 02/09/2021

Compared with the usual vaccine development process, we have witnessed an unprecedented effort resulting in multiple COVID-19 vaccines developed in under a year. It is only natural that people have many questions, but the sheer amount of information might be overwhelming. Here we answer some of the frequently asked questions on COVID-19 vaccines. 


Which COVID-19 vaccines have been approved?

Vaccines are being approved by local authorities, so there are no vaccines approved globally. So far, several vaccines have been approved in various parts of the world. However, the term “approved” is used a bit loosely, as it is not always a proper approval, but often a conditional/temporary authorization given the severe situation. The first was the Gamaleya Sputnik V vaccine, soon followed by another Russian vaccine EpiVacCorona by Vector Institute. Then, the first approved “western” COVID-19 vaccine Pfizer-BioNTech, followed by the Moderna and AstraZeneca vaccines. There are also several Chinese vaccines, including the CanSino, Sinopharm, Sinovac, and Sinopharm-Wuhan vaccines, and an Indian vaccine COVAXIN by Bharat Biotech


Which COVID-19 vaccine is the best?

To be approved, each vaccine candidate must prove to be safe and effective in rigorous clinical trials. Since it is generally not possible to choose which COVID-19 vaccine to get – you are lucky to be eligible for any COVID-19 vaccine as they are in high demand and limited amount – these discussions are pointless. Moreover, what would be the criteria to select the best vaccine? Is it the one with the highest efficacy against moderate and severe COVID-19, or the one that results in the least COVID-19-related hospitalizations? The most affordable option or the most manageable storage conditions? The one-dose-only option? The one with the least cases of documented side effects? It is important to remember that the approved vaccines are not against each other, but they will all play critical roles in ending the pandemic. 


Why are some COVID-19 vaccines so temperature-sensitive?

The temperature requirements of COVID-19 vaccines depend on the type of the vaccine (its platform). Viral vector vaccines can be kept at common refrigerator conditions (2°C to 8°C or 36°F to 46°F). However, mRNA vaccines – the Pfizer vaccine in particular – requires a much lower temperature for long-term storage and transport – about -80°C to -60°C (-112°F to -76°F)1. This is due to its character, as mRNA is very fragile and easily degraded at higher temperatures. Why the Moderna vaccine, which is also an mRNA vaccine, can be stored at normal freezing conditions of -25°C to -15°C (-13°F to 5°F)2 is likely related to the type of lipid nanoparticles that coat the mRNA3. COVID-19 vaccines are the first mRNA vaccines to be approved, so it is an unprecedented requirement that complicates vaccination logistics. 


Can you get a COVID-19 vaccine when pregnant?

Here is where we lack solid data – we do not know whether it is truly safe for pregnant women to get vaccinated against COVID-19. This does not mean that it is not safe – just that it hasn’t been sufficiently tested. Based on the lack of data, the WHO recommends not to use the Pfizer or Moderna vaccine in pregnancy unless the benefit outweighs the potential vaccine risks, i.e., pregnant women at high risk of exposure and those in a high-risk group for COVID-19 due to their comorbidities4. Developmental and reproductive toxicology studies in animals have not shown harmful effects in pregnancy. Further studies are planned for pregnant women in the coming months, and the recommendations will be updated accordingly. Ultimately, it might depend on your local authorities – in the USA, getting vaccinated is a personal choice for pregnant women5. On the other hand, in the UK, the regulators discourage pregnant women from COVID-19 vaccination programs6


Are children eligible for a COVID-19 vaccine?

Just like the vaccine is not recommended for pregnant women, the vaccine is not available for children because of the lack of data. The vaccine’s safety and efficacy must be tested in children before being widely used for their vaccination. Nevertheless, clinical trials are underway to get the COVID-19 vaccines approved for use in children. Age de-escalation testing has already started with both the Pfizer and Moderna vaccine in children 12 and above7. After the results from their adolescent trials are available, the testing will focus on even younger children (aged 5 to 11). However, it is still months at best from being available to these age groups.


Can I pay to get the COVID-19 vaccine privately?

The option to pay for a COVID-19 vaccine privately and skip the queue is (at least officially) not available. Fortunately, major vaccine producers ruled out any plans to supply the vaccine to the private sector8. However, even if this becomes an option in the future, the vaccine manufacturers are currently fully booked and must fulfill their previous orders and obligations before selling to the private sector. 


Will COVID-19 vaccination be required for travel?

It is possible that in the future, some countries might demand proof of COVID-19 vaccination before you can travel there. Nevertheless, the vaccination speed is very different in various countries, so it will not likely be a requirement anytime soon. Also, at this point, it is not known whether the vaccinated people are still able to spread the virus or how long the vaccine-provided immunity will last. With the high number of COVID-19 cases and a small number of people vaccinated so far, the current trend is still leaning towards travel restrictions and border closing.




Image by Arek Socha from Pixabay