COVID-19 Vaccination: Timing, Number of Doses Required For Full Protection

Currently, one of the effective ways to stay protected against COVID-19 virus is to get a shot of any of the approved vaccines. Since the first jab was given in December 2020, several questions have been asked about efficacy and safety. Although medical experts and scientists are still studying the virus, symptoms and the vaccine, the World Health Organization (WHO)  has assured of its safety and effectiveness in fighting the pandemic.

Is a single dose enough to protect me?

According to the requirements of some of the approved vaccines, (Pfizer-BioNTech and Moderna), individuals will be fully protected from coronavirus after they have taken two doses of the vaccine. The Center for Disease Control and Prevention (CDC), has advised people to get their second shot, even if they have side effects after the first shot, unless a vaccination provider or their doctor tells them not to get it.

In Ghana, for instance, the first set of vaccines was rolled out on March 2, 2021, giving people the opportunity to get their first dose. After more than 10 weeks of receiving the first dose, people who received their first jab are required to take a second dose as has been prescribed by global health agencies.

However, here’s one question that is still bothering several people: Do I necessarily need a second dose?

The answer to this question depends on the type of vaccine one’s country has been administering. According to the CDC, people who receive a Pfizer-BioNTech or Moderna COVID-19 vaccine will need 2 shots to get the most protection.

A third vaccine, AstraZeneca, also requires a second shot to be effective. However, the Janssen COVID-19 Vaccine by Johnson and Johnson requires only a single dose. 

A December 2020 Pfizer data  report suggested that the  Pfizer-BioNTech vaccine is roughly 52% effective after the first dose. This report from a preclinical trial demonstrated that a single dose was not enough to maximize one’s protection from the virus. The  report further indicates that taking the second dose is  95% effective at preventing the disease after a week.

What should be the timing intervals between the first and the second shot?

Although Pfizer-BioNTech and Moderna require a second shot, the interval between when one should get a second shot differs. According to the CDC, people who receive the Pfizer-BioNTech COVID-19 Vaccine would have to get  their second shot three weeks (or 21 days) after their  first.

For other vaccines like Moderna, the CDC states that the second shot should be taken four weeks (or 28 days) after the first.

For Vaccines like AstraZeneca which was administered in Ghana, health experts say the second dose can  be administered between four and 12 weeks after the first shot.

For Pfizer-BioNTech and Moderna, it is advised that a second shot be taken as close to the recommended three-week or four-week interval as possible. However, in cases where there is a  delay, the second  dose may be given up to six weeks (42 days) after the first dose, if necessary.

Research and clinical trials have demonstrated that  COVID-19 vaccine protection starts from about two weeks after the second dose.

Can I take the second dose earlier than recommended?

No. According to the CDC, one should not get the second dose earlier than recommended by manufacturers and health professionals. This is because there is currently limited information on the effectiveness of receiving your second shot earlier than recommended or later than six weeks after the first shot.

However, people do not have to restart the entire vaccination process if they  receive the second shot of COVID-19 vaccine earlier or later than recommended.

Show More

Related Articles

Make a comment

Back to top button