How long does a pfizer vaccination last

The effectiveness of Pfizer's Covid-19 vaccine steadily declines over time, dropping to about 84% for vaccinated people about four to six months after getting their second dose, according to CEO Albert Bourla.

Table of Contents Show

How quickly does the vaccine work and how long does the protection last?
Will vaccines be able to eliminate or eradicate COVID-19?
If an individual did not develop high antibody titers after vaccination, should he/she be vaccinated again with another vaccine? Is it safe? What should be an interval between two vaccinations?
Is a COVID-19 booster shot needed?
Are COVID-19 vaccines effective against new variants of concern of the SARS-CoV-2 virus?
To what extent can vaccines prevent people from getting infected with COVID-19?
Why do immunocompromised people need an additional dose of COVID-19 vaccines?
Why are some vaccinated people getting sick with COVID-19 and in some cases being hospitalized?
Why has Omicron been designated a variant of concern, and can it affect people who are already vaccinated?
Will variant-specific vaccines be needed in the near future?
Is the immunity that the current COVID-19 vaccines provide waning over time?
When should a person be considered fully vaccinated?
Does vaccination prevent long COVID?
Are COVID-19 vaccines effective against Omicron subvariant BA.2?
Can COVID-19 vaccines stop transmission of Omicron and its subvariants?
Learn about COVID-19 vaccines and vaccination on the go
Don't miss a thing
COVID-19 vaccines and vaccination explained

The comments, made on Wednesday on CNBC's "The Exchange," are based on the findings of a new company-funded study that has yet to be peer reviewed. It comes as the drugmaker clashes with U.S. health officials over the need for a third Covid vaccine dose to boost immunity protection.

The study found the vaccine's effectiveness was strongest, at 96.2%, between one week and two months after receiving the second dose. It declined an average of 6% every two months, according to the study, which signed up more than 44,000 people across the U.S. and other countries. The efficacy after "four to six months was approximately 84%," Bourla said.

Pfizer sells $7.8 billion in Covid shots in the second quarter, raises 2021 guidance on vaccine sales

"We have seen also data from Israel that there is a waning of immunity and that starts impacting what used to be what was 100% against hospitalization. Now, after the six month period, is becoming low 90s and mid-to-high 80s," Bourla said.

"The good news is that we are very, very confident that a third dose, a booster, will take up the immune response to levels that will be enough to protect against the delta variant," the executive added, referring to the highly contagious virus strain that's dominant in the U.S. and other countries around the globe. It's not uncommon for vaccines to decline in effectiveness over time, Bourla stressed, adding there's precedent for three-dose vaccines for other diseases.

Pfizer plans to formally submit data to U.S. regulators about the benefits of a third Covid vaccine dose by mid-August, Bourla said.

Earlier this month, when Pfizer first announced its plans, the Food and Drug Administration and the Centers for Disease Control and Prevention issued a joint statement that pushed back on the company, saying "Americans who have been fully vaccinated do not need a booster shot at this time."

The CDC and the World Health Organization don't recommend Covid booster shots at this time.

Dr. Kate O'Brien, WHO's director of immunization, vaccines and biologicals, said Wednesday the organization is still researching whether a booster shot is needed to increase protection.

"We're very clear on this, there's not enough information to provide a recommendation at this point," O'Brien said in a Q&A interview posted on the organization's social media accounts. "Again, this is a very hot topic, and there's a lot of research going on to be able to provide an evidence-based recommendation."

The results of Pfizer-backed study surfaced a day after the CDC reversed course on its prior guidance and recommended fully vaccinated Americans who live in areas with high Covid infection rates begin to wear face masks indoors again.

Coronavirus cases have jumped nationwide in recent weeks, a surge public-health officials attribute to the delta variant. While officials say the majority of Covid hospitalizations and deaths are in unvaccinated people, the delta variant is so contagious that vaccinated individuals can transmit the virus as easily as unvaccinated people, even in asymptomatic cases, CDC Director Rochelle Walensky said Tuesday.

It generally takes 1-2 weeks following COVID-19 vaccination for the body to build immunity against the virus.

Duration of protection differs per vaccine and may be influenced by who receives it. People who are immunocompromised tend to develop a weaker immune response to the standard number of vaccines doses, and therefore need an additional dose in the primary series. Immunity against mild infection starts to wane in the months following vaccination, especially among older adults. This is why many countries have introduced a booster dose, starting with the older age groups.