Medical professionals are skeptical on a fourth Covid vaccine dose

Read Time:4 Minute, 10 Second

There hasn’t been enough research on how much protection a fourth dose can offer, medical professionals told CNBC.

Justin Sullivan | Getty Images

Countries are beginning to offer a fourth dose of the Covid-19 vaccine to vulnerable groups, but medical professionals are undecided on whether it would benefit the wider population.

The US Food and Drug Administration has so far authorized a fourth shot only for those aged 50 and above, as well as those who are immunocompromised. And the US Centers for Disease Control and Prevention was skeptical of the need for a fourth dose for healthy adults in the absence of a clearer public health strategy.

Those decisions came as a study from Israel found that although a fourth dose of the Pfizer-BioNTech vaccine offers protection against serious illness for at least six weeks after the shot, it provides only short-lived protection against infection, which wanes after just four weeks .

No ‘good evidence’ yet

The medical consensus so far is that there hasn’t been enough research on how much protection a fourth dose can offer.

The World Health Organization hasn’t given an official recommendation on a fourth dose, and “there isn’t any good evidence at this point of time” that it will be beneficial, said WHO chief scientist Soumya Swaminathan.

“What we know from immunology is that if you give another booster, you will see a temporary increase in the neutralizing antibodies. But what we’ve also seen is that these neutralizing antibodies will wane quite rapidly,” Swaminathan told CNBC in an interview.

A fourth dose doesn’t really do much of anything … I’m not sure we need to get out and just jump up and down screaming that everybody needs to get aboard.

Paul Goepfert

professor at the University of Alabama

“This happened after the third dose. And it’s happened again after the fourth dose,” she added.

Paul Goepfert, professor of medicine at the University of Alabama, shared that view, saying that “a fourth dose doesn’t really do much of anything … I’m not sure we need to get out and just jump up and down screaming that everybody needs to get aboard.”

Since the study from Israel shows the fourth dose can provide protection against serious disease, countries such as Israel, Denmark and Singapore have made a second booster shot available to high-risk groups.

“Rather than saying that the protection wanes, I would say that this boost effect is strongest shortly after the vaccine was administered, but that it remains protective overall,” said Ashley St. John, an associate professor at Duke-NUS Medical School.

“Importantly there was no waning of protection against severe disease, which is the most key effect of vaccination we aim to achieve,” she added.

Annual booster shots?

Questions are being raised over the need for more booster shots as the emergence of more Covid variants may require more targeted vaccines.

Anthony Fauci, White House chief medical advisor, told NBC News in January that people may need to get booster shots every year or two.

However, blanket vaccine approaches may not continue to work.

It is possible that high-risk groups — such as the elderly — may need an annual vaccine, said Swaminathan. But “it’s not clear whether a healthy adult is going to need a regular annual shot.”

It’s also important to note that the current vaccines being administered may not work for future variants of Covid-19, she said.

If the virus “changes so much that you need to change your vaccine composition, then you won’t need another shot,” Swaminathan added. “The challenge of changing the vaccine composition is that you’re always playing catch-up.”

Goepfert said “only time will tell” how long more the population has to take booster shots, but the safest approach would be to “plan on a booster every year, and maybe combine it with the flu vaccine.”

Omicron subvariant

The WHO announced on Tuesday that weekly new Covid deaths had fallen to the lowest level since March 2020.

But the more contagious omicron BA.2 subvariant remains the dominant strain in the United States, making up 68.1% of all cases in the country during the week that ended on April 23, according to data from the CDC.

Although experts predict that the BA.2 subvariant is unlikely to be more severe than the original omicron strain, it should remain a concern.

“I do think infections are going to continue … it’s taken over most parts of the country, said Goepfert. “But in terms of severe infections, I think that’s going to continue to be less and less.”

Patients from locations with adequate vaccination coverage would experience only “mild or manageable disease” and this would reduce “burden on the healthcare system compared to waves of Covid pre-vaccines,” St. John said.

“Just like studying for an exam, a vaccine booster can trigger immune system memories and increase performance during the real test,” she added.

If you want to know more about business please go to

0 %
0 %
0 %
0 %
0 %
0 %
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners. View more
Cookies settings
Privacy & Cookie policy
Privacy & Cookies policy
Cookie name Active

Who we are

Suggested text: Our website address is:


Suggested text: When visitors leave comments on the site we collect the data shown in the comments form, and also the visitor’s IP address and browser user agent string to help spam detection. An anonymized string created from your email address (also called a hash) may be provided to the Gravatar service to see if you are using it. The Gravatar service privacy policy is available here: After approval of your comment, your profile picture is visible to the public in the context of your comment.


Suggested text: If you upload images to the website, you should avoid uploading images with embedded location data (EXIF GPS) included. Visitors to the website can download and extract any location data from images on the website.


Suggested text: If you leave a comment on our site you may opt-in to saving your name, email address and website in cookies. These are for your convenience so that you do not have to fill in your details again when you leave another comment. These cookies will last for one year. If you visit our login page, we will set a temporary cookie to determine if your browser accepts cookies. This cookie contains no personal data and is discarded when you close your browser. When you log in, we will also set up several cookies to save your login information and your screen display choices. Login cookies last for two days, and screen options cookies last for a year. If you select "Remember Me", your login will persist for two weeks. If you log out of your account, the login cookies will be removed. If you edit or publish an article, an additional cookie will be saved in your browser. This cookie includes no personal data and simply indicates the post ID of the article you just edited. It expires after 1 day.

Embedded content from other websites

Suggested text: Articles on this site may include embedded content (e.g. videos, images, articles, etc.). Embedded content from other websites behaves in the exact same way as if the visitor has visited the other website. These websites may collect data about you, use cookies, embed additional third-party tracking, and monitor your interaction with that embedded content, including tracking your interaction with the embedded content if you have an account and are logged in to that website.

Who we share your data with

Suggested text: If you request a password reset, your IP address will be included in the reset email.

How long we retain your data

Suggested text: If you leave a comment, the comment and its metadata are retained indefinitely. This is so we can recognize and approve any follow-up comments automatically instead of holding them in a moderation queue. For users that register on our website (if any), we also store the personal information they provide in their user profile. All users can see, edit, or delete their personal information at any time (except they cannot change their username). Website administrators can also see and edit that information.

What rights you have over your data

Suggested text: If you have an account on this site, or have left comments, you can request to receive an exported file of the personal data we hold about you, including any data you have provided to us. You can also request that we erase any personal data we hold about you. This does not include any data we are obliged to keep for administrative, legal, or security purposes.

Where we send your data

Suggested text: Visitor comments may be checked through an automated spam detection service.
Save settings
Cookies settings