In addition to Pfizer, the results of Moderna and AstraZeneca clinical trials are expected to be equally positive – Seven critical questions and answers about vaccines

In the final stretch for the approval of a vaccine against the new SARS-CoV-2 coronavirus is humanity. The very positive preliminary results from Phase 3 of the clinical trials of the Pfizer / BioNTech BNT162b1 vaccine have led to genuine optimism that COVID-19 infection will eventually be effectively treated.

Yesterday, Pfizer announced that the vaccine has 90% efficacy in a sample of 94 confirmed cases of COVID-19.

Equally positive results are expected from the other two powerful “opponents” of BNT162b1, mRNA-1273 of Moderna and AZD1222 of AstraZeneca/University of Oxford, which will be published in the near future.

But since both COVID-19 and SARS-CoV-2 are new paradoxes in our lives, there are some reasonable questions about the role of vaccines in pandemic management.

Here are seven questions and answers about the new coronavirus vaccine:

1. How many doses of the vaccine should I take?

As everything shows from the data so far of all Phase 3 clinical studies involving the three predominant vaccines (BNT162b1, mRNA-1273 and AZD1222) two doses of the vaccine are needed with a difference of 28 days in order to provide adequate immunoprotection. Of course, there is Johnson & Johnson’s vaccine under development, JNJ-78436725, which shows in Phase 1 studies to achieve adequate single-dose immunosuppression.

2. Should I continue to wear a mask if I am vaccinated against COVID-19?

According to the US Centers for Disease Control and Prevention (CDC), yes we should continue to wear our mask properly (covering our nose and mouth) to protect ourselves and others.

3. If I have COVID-19 and have recovered, do I need the vaccine?

At present, the estimates of how long the physical immunity of someone who has recovered from COVID-19 lasts are confusing. Preliminary evidence suggests that this immunity may not last long, which is why many targeted studies are underway to answer this key Query. So for the time being no regulator can clearly answer whether people who have recovered from COVID-19 infection should also have the vaccine or not.

4. Is it necessary to get vaccinated against COVID-19 if I follow the basic protection measures (mask, distances, good hand hygiene)?

To stop the pandemic, experts believe that all available means should be used. Vaccines are the way to boost the immune system so that our body is ready to deal with SARS-CoV-2 when confronted with it. The use of the mask and the observance of distances help decisively in reducing the chances of being exposed to the new coronavirus or if we are carriers to transmit it to those around us. According to the CDC, vaccination against COVID-19 and compliance with all protection measures in combination is the best way to protect against the new coronavirus.

5. Does the immunity of someone who has recovered from COVID-19 last longer than the protection of the vaccine?

Natural immunity as mentioned above is not known exactly how long it lasts and can vary from person to person. And because SARS-CoV-2 is new to scientists, it is also not known how long the protection that vaccines will last.

6. If I have been vaccinated against COVID-19 can I pass SARS-CoV-2 to other people?

Theoretically, if the vaccine has been given correctly and the vaccinated person has developed an adequate immune response then transmission of the virus to others is not possible. However, as research is still ongoing the final answer will be given in practice.

7. What percentage of the population should be vaccinated to achieve “herd immunity” to COVID-19?

A study published in the American Journal of Preventive Medicine in June, based on a computational algorithm, estimated that about 60-70% of the world’s population should be vaccinated to stop the spread of SARS-CoV-2 in the community.