Name: Big questions about the Covid booster shot, answered
Uploaded: 2022-02-18T23:38:00.000Z
Duration: 7 min 50 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

In September 2021, the CDC recommended Covid-19 booster shots,

an additional vaccine dose, for the elderly

That echoed the booster shot rollout  in places like the UK and Singapore.

But in November, the CDC announced  a new recommendation:

And that idea had been a contentious question among scientists.  

"I do believe that all of us are going  to need another shot at some point."

"It's much more of a gray area for  younger people, particularly under 50s."

"I don't think we should get hung up  on should, may...

"FDA's Dr. Marion Gruber and Dr. Phil Krause

say there's currently no need for boosters for the general population."

Dr. Celine Gounder was one of those scientists.

She wasn't convinced that we all  needed more shots.

So, to help me figure out what's going on with boosters,

GOUNDER: I had not planned to get boosted, and yesterday scheduled a third dose.

And that's really a decision that was made based on the emergence of omicron. 

To start us off, can you sort of just  walk us through

you're stimulating different branches of your immune system. 

You're stimulating B cells,  T cells, antibody levels.

Those antibody levels are what protect you robustly against infection,

What we saw from the data in Israel, as well as other countries like the US, is

you saw a waning antibody levels at six months after the second dose.

But Dr. Gounder emphasized that  charts like this shouldn't alarm us.

GOUNDER: Once those antibodies fade away, the B cells are still there.

B cells are these little factories to make antibodies. 

So when you get re-exposed  to the virus,

the B cells recognize the virus and kick back into gear

You're not fully protected  against all infection,

but you still have very strong, very long-lived memory B cell responses

that are still there to protect you from severe disease, hospitalization, and death. 

So if we still have that protection  from severe cases,

why do we need more antibodies from a booster?

GOUNDER: There are certain groups in which we do see a reduction in protection

against even some of those more severe outcomes.

In addition, people who are highly immunocompromised

also do benefit from getting additional doses of vaccine.

That was the reasoning behind initially  limiting boosters to the vulnerable:

that while boosters for all adults in general could help replenish antibodies

they weren't necessary for  preventing severe cases,

which vaccines continue to do effectively for most people.

But many scientists like Dr. Gounder  have changed their mind on that stance

based on the information available about the omicron variant at the time of this video.

GOUNDER: Now that you've had the rise of  the omicron variant,

it's a different conversation about boosters.

The concern about  the Omicron variant is that

our vaccines may not fully protect  against this variant,

which has more than 30 mutations  in the spike protein. 

B cells that would have recognized earlier strains of the virus

that your memory immune responses  don't recognize it.

But that's a prediction based on looking at the genetic sequence.

you can override that relative immune evasion.

It's not clear yet whether or not we'll need a new vaccine for the new variant.

That was actually a question companies like Pfizer had with the other variants, too.

So even though there are still  a lot of unknowns about omicron,

experts like Dr. Gounder say boosters  may be a good tool against it,

especially if it turns out to be as bad  as some fear.  

So at what point after our first round  of vaccinations

GOUNDER: So you should wait six months  after your second dose of COVID vaccine,

if you got the Pfizer or Moderna vaccine,  before getting a boost,

and you should wait two months after getting the Johnson & Johnson vaccine

To really get to peak antibody levels, you really want to wait about two weeks. 

So if you're, say, planning to go visit family over the holidays,

I would recommend getting that  additional dose of vaccine,

that booster dose, about two weeks  prior to travel. 

And that booster doesn't have to be the same one you originally got. 

GOUNDER: The NIH conducted a study  looking at,

do you start with Johnson & Johnson,  Pfizer, or Moderna,

and then do you boost with Johnson & Johnson, Pfizer, or Moderna?

The study found that  not only is mixing vaccines safe:

In the US, if you got initial doses of  an mRNA vaccine,

But it's recommended that if you got  Johnson & Johnson first,

it's most effective to get boosted with an mRNA vaccine.

Similarly, in countries like Germany and Korea,

most people who got AstraZeneca  will be offered an mRNA vaccine. 

GOUNDER: There is some thought that the different vaccine technologies

teach the immune system to recognize the spike protein in slightly different ways,

and that as a result, the immune system, you could say, remembers better.

Considering that the vaccines have been so unequally distributed around the world,

should we be concerned about  the ethics of getting a third shot

when so many people haven't even had their first?

GOUNDER: I think we should be worried about that at a policy level, at a macro level,

but whether you yourself as the individual choose to get a booster dose or not

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Big questions about the Covid booster shot, answered

vulnerable

immune

recognize

pandemic