The SARS-CoV-2 virus, the virus that causes COVID-19,
continues to evolve.
And so the Delta variant is another variation of the virus
that seems to be more contagious
and potentially can cause more severe disease.
We do think that it's probably about twice as contagious
as prior variants.
Scientists don't fully understand why it's more contagious,
but I think part of it probably is because
it causes more virus to be replicating
in people who are infected.
So vaccines are still very effective
against the Delta variant
and to most of the variants
that are circulating in our community.
Vaccines prevent infection.
They also prevent severe illness,
such as hospitalizations and deaths.
There is some evidence that suggests
that the Delta variant may cause more severe disease,
but it's still inconclusive at this time.
What we can say is
in countries where vaccination has been very widespread,
the relative proportion of deaths
has actually been quite reasonably low.
And so it just lends evidence to the idea
that the vaccinations are working and are saving lives.
With people getting infected,
at some point the population will achieve herd immunity,
but it's just unclear
whether we're going to do it the easy way with vaccines
or the harder way with natural infection,
and I'm hoping most people will choose vaccination.
There's some data to suggest that people who have moderate
to severe immunocompromised states may not respond
to the initial two doses of an mRNA vaccine.
And so the FDA and the CDC have made recommendations
to allow for a third dose
in hopes of increasing vaccine effectiveness
in this population.
And this includes people who have cancer,
getting chemotherapy,
people who have received transplants,
and people who receive immunosuppressive medications.
It's hoped that for vulnerable populations,
particularly the immunosuppressed population,
that a third dose will keep people from getting sick,
ultimately getting hospitalized or even dying.
But it's important to note
that patients who have baseline immunocompromised states
may not respond to that third dose
and still need to practice precautions against COVID-19.
In terms of safety of a third dose,
we believe that the safety of the first two doses
has already been well studied.
And so there's ample evidence from millions of patients
who have received the first two doses
that these vaccines are highly effective and highly safe.
And so the safety of a third dose,
we think would fall in line with what we've had before.
Some people might wonder if people need a booster vaccine.
Does that mean that the vaccine is not effective
in the first place?
And I think the answer is,
while we know that the vaccines are effective
but that there is increasing evidence to show
that the effectiveness might wane over time.
And so for people who are vulnerable,
especially the older persons or people with comorbidities,
there is interest now in thinking about booster vaccines.
Right now the priority is for people who are
immunosuppressed, because they're least likely to have
responded to their first two doses.
But later on,
the US government has signaled that there are also plans
to give booster doses to everybody
who has received their initial primary series of vaccine.
I think the Delta variant surge
has humbled us in a way,
because we've realized that the vaccines alone in some cases
may not be foolproof
in preventing either infection or transmission.
And so in those situations
where the community rates of transmission are high,
we realized that it takes more than just vaccines.
Sometimes it takes other layers of protection,
such as wearing face masks during indoor activities.
A common question is, when will indoor masking go away?
And I think this really depends
on just the risk of COVID-19 virus
circulating in our community.
If there is a high level of circulation in the community,
then it makes sense
to layer on that additional safety measure
of wearing an indoor mask.
And that just means that the vaccines themselves
are doing a very good job, but we need more than just that.
There are other situations
where indoor masking is important,
and that's in situations where we know that transmission
can lead to really bad outcomes,
and health care settings are a good example of that,
where we have a lot of vulnerable people
being cared for here.
And so indoor masking is likely going to stay for a while
in health care settings.
So after about eight or nine months now
of experience with the vaccines,
we know that they do an extremely good job
of preventing severe illness and death.
So if you are fully vaccinated for COVID,
you're 20 to 25 times less likely to end up on a ventilator
or dying.
So this is very important.
We think that the vaccines
turn something that's potentially deadly
into something that acts more like a common cold or the flu.
And so that's why we're stressing
that everybody needs to get vaccinated,
particularly if you're working in a high-risk setting,
such as in health care,
and particularly if you have loved ones in your household,
people who you are around
who may be vulnerable to COVID-19.
This is something that we can all do together for ourselves
and for loved ones
and for our fellow people in the community.