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Epidemiologists Answer Questions About The Rise In COVID Cases In N.H.

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There’s been an uptick in COVID-19 cases in New Hampshire in the past few weeks, and the Delta variant of the virus is rapidly spreading throughout the U.S. This week, the total number of people in New Hampshire who’ve tested positive for the virus since last March hit 100,000.

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NHPR asked our listeners to submit their questions about how to stay safe during this phase of the pandemic and about the state’s current response.

Dr. Benjamin Chan, state epidemiologist, and Dr. Michael Calderwood, infectious disease expert and chief quality officer for Dartmouth-Hitchcock Medical Center, joined NHPR’s Morning Edition host Rick Ganley to answer those questions.

Four things you should know about this phase of the pandemic, according to Dr. Chan and Dr. Calderwood:

  • Cases linked to the Delta variant are spreading, but they still remain the minority of cases in New Hampshire (Editor’s note: The state does not test every positive case for the Delta variant.)
  • The best way to protect yourself against COVID, including the Delta variant, is to get fully vaccinated.
  • The Department of Health and Human Services issued guidance for COVID safety in schools this fall, but is allowing local districts to decide what requirements to put in place.
  • People who are unvaccinated or immunocompromised should still wear masks indoors in public spaces, especially when social distancing is not possible.

Rick Ganley: Just about every listener who wrote in had a question about the spread of the Delta variant here in New Hampshire, not surprisingly Dr. Chan. I want to start with you. What is the current percentage of COVID cases that are linked to the Delta variant and how difficult is it for the state to get a sense of how common that variant is here?

Ben Chan: Yeah, so, so the Delta variant is one of the newest variants of concern that is spreading around the country and is actually the predominant variant identified in many other parts of the United States. Thankfully, it's still in the minority, largely in the New England region and in New Hampshire. But we are starting to see increases in the number of detections of Delta variant cases. So the total number of people detected so far that have been infected with the Delta variant is now at 23. Eight of these are new in the last week. So we are beginning to see an increasing number of infections due to the Delta variant.

Rick Ganley: Now, with the rise in various variants and various reports, we're getting about possible effectiveness of vaccines. I'm wondering how worried you are. You know, a lot of people have written to us with basic questions about how to live their lives in this stage of the pandemic. Pat from Rye asks, should I still be wearing a mask in places like the supermarket, outdoor venues with large crowds, even though I'm fully vaccinated?

Ben Chan: Yeah, it's a great question. And I think it's one of the things that we are all re-evaluating is, you know, whether the level of vaccination we have achieved in New Hampshire and nationally is going to be sufficient to control, um, the circulation of this new Delta variant. I think what we're going through right now really is a stress test of all of the vaccination work we've collectively done over the last seven months. You know, the vaccines are still effective against the Delta variant, but no vaccine is going to be a hundred percent. And so, you know, consistent with guidance, we put out a month ago, we continue to recommend that people consider wearing face masks when they're in particularly indoor, high-risk, locations. So crowded locations where people are coming into close contact with one another and this is especially important if they are either unvaccinated or not fully, or if they might be susceptible to more severe disease due to a health condition. I think that there are locations where we certainly continue to recommend people use mitigation measures, prevention, strategies, like face mask use. But to be clear, these kinds of prevention strategies are meant to be a temporizing or bridging measure until we can get more and more people vaccinated.

Rick Ganley: I want to get to that in vaccination rates in general, in a moment, but Dr. Calderwood I want to ask what guidance that you're giving to people right now.

Michael Calderwood: So I think what Ben has said is quite accurate. What we know is that the current vaccines, if we're looking at the two mRNA vaccines, they remain 80 to 90 percent effective in preventing symptomatic COVID-19 from the Delta variant. And if you look at prevention of severe disease leading to hospitalization, it's well above 90%. And so, while we do see some breakthrough infections. They tend to be fairly mild and those that are getting hospitalized and those who are dying around the country are really the unvaccinated and those who've received full vaccination and are two weeks beyond their last dose are protected. Now there may be environments, as Dr. Chan has mentioned, where you may be at higher risk because those around you are not vaccinated. It's a larger crowd, you have health conditions. So what I would say to folks is if they're unvaccinated, the mask is still quite important. And if they have an immune condition where they may not have developed as robust a response to the vaccine they should also be thinking about social distancing, as well as mask use.

Rick Ganley: Dr. Chan, how big of a concern should these breakthrough cases be for folks out there who are fully vaccinated? Are you worried that they could somehow be carriers of COVID even though they have been vaccinated?

Ben Chan: Yeah, it's a great question. And, first let me say that, um, vaccine breakthrough cases are still the minority of cases that we're seeing. Um, most of the cases, certainly the severe disease, the severe infections that, um, lead to hospitalization, or even deaths are in people that are not fully vaccinated, um, but vaccine breakthrough infections doesn't mean that the vaccines aren't working. And so there's good, and even new evidence emerging, there was an article published in the New England Journal of Medicine, you know, two or three weeks ago, um, quantifying that even in people who are fully vaccinated and develop an infection, a vaccine breakthrough infection, the vaccine is still beneficial in terms of lowering the amount of virus that they're shedding into their environment, decreasing the time that someone might be shedding virus into the environment around them, limiting the symptoms and the severity of symptoms, uh, fewer sick days that, that people have if they develop, symptoms. So, you know, vaccines are both very effective at preventing, you know, disease and asymptomatic infection, uh, and they're being shown to be effective likely at preventing spread and transmission of infection, if someone, by chance, in the uncommon event, that they develop a vaccine breakthrough infection.

Rick Ganley: How is the state keeping track of that number of vaccinated people who are testing positive?

Ben Chan: Yeah. So, we continue to get reports of every person diagnosed with COVID-19, uh, and well, numbers are low. We're able to continue to investigate those cases and trying to determine someone's vaccination status. And so part of our investigation into people who test positive is to ask about vaccination status and determine, you know, when they got their vaccine doses relative to onset symptoms, and whether it truly qualifies as, as a true vaccine breakthrough infection, you know, there are certainly cases where somebody might be partially vaccinated and then, you know, before they can get their, for example, second dose of the Pfizer or Moderna vaccine develop an infection. We don't consider that a true vaccine breakthrough infection because they're not fully vaccinated, but this is all part of the reporting and contact investigation that occurs with public health.

Rick Ganley: Dr. Calderwood, I'm wondering if, if you can shed some light on this, of course, the reported numbers are one thing, but if someone is fully vaccinated, but is exposed to the virus and does not have any symptoms or very mild symptoms, and doesn't go for a test, we may not know the true number, right?

Michael Calderwood: Well, I think that's true. I think that right now, we are assuming that those that have an exposure outside the home and are fully vaccinated are quite protected. We know that transmission within homes has been quite a bit higher. And so even if you're vaccinated within the home, that's what case where we might consider testing to understand who else has been impacted even if they are vaccinated. So that is something that could be done to investigate that. I think what we know is that with this Delta variant, transmission is higher. And so amongst those who are unvaccinated, an infected individual is likely to spread to five to eight additional people. And the risk of hospitalization is four times higher than with the original circulating variant from a year and a half ago. So it is getting more aggressive and the vaccine is really your best defense against both transmission and severe disease.

Rick Ganley: That higher rate for hospitalization is for unvaccinated people, correct?

Michael Calderwood: That is correct. Yes.

Rick Ganley: The American Academy of Pediatrics is recommending everyone over the age of two wear masks when schools reopen. I know the CDC is recommending face masks indoors for students and staff who are unvaccinated, but New Hampshire is leaving it up to local districts to decide what safety measures to put in place. I'm wondering, why not issue any specific requirements for schools, Dr. Chan?

Ben Chan: Yeah. So the requirements that were in effect for schools last year were under the state of emergency, the executive orders, that were out there. And as you know, we've talked about frequently over the last month those state-level requirements have gone away. That doesn't mean that there isn't guidance or information that's being put out there to help schools think through how to safely reopen in the fall, right. There’s the new CDC guidance. There's the AAP guidance that's the American Academy of Pediatrics. There are the general, you know, principles, prevention strategies outlined in the New Hampshire universal best practices. There's the experience that schools have from last year. But, you know, understanding that perhaps a lot of this is confusion is confusing. There's different guidance that's out there. We are continuing to engage with our school and child care partners. We had actually a call with them yesterday, talking through some of the existing guidance that is out there, put out some additional thoughts and considerations and, and even a suggested public health approach to trying to implement all of this guidance that is out there. So we are continuing to work with our schools to help them think through the, perhaps some of the confusing guidance that's out there.

Rick Ganley: Well I know some school systems have said, we're not going to require masks of vaccinated folks, and I've heard some schools say we are. So it seems like it's going to be a patchwork across the state.

Ben Chan: Yeah. One of the, I think, key recommendations here is that how schools apply the prevention strategies is going to vary location by location. And it really, you know, something like face mask use needs to be based on a local assessment of risk. And so we continue to base our recommendations, our public health recommendations for mitigation measures like face mask use on a local assessment looking at the level of COVID-19 in the community. And so, you know, there are some areas that we have highlighted that generally there's agreement on between us and CDC and others, for example, face mask use in the outdoor locations is generally no longer recommended, but when it comes to some of these questions around, well, should schools recommend, should they require face masks and face masks to indoors? It is going to vary by location and it's going to be, it's going to vary by location based on sort of an assessment of their ability to implement other mitigation measures and local risks.

Rick Ganley: Sure. Andrea from Hopkinton asks us, do you believe that school children under the age of 12 who are not eligible for the vaccine right now should continue to wear masks full-time in school? I wonder if you could field that one, Dr. Calderwood.

Michael Calderwood: That's a great question. I think we are getting a lot of guidance from our local pediatricians. I think we have to understand the real impact that changes in education have had over the past year and a half and make sure that what we're putting in place really both keeps our children and their families safe but also allows them to return to education, which really has been, to a degree, impacted, by this. I mean, schools have done an amazing job of keeping children in school being educated. We had between 6 and 7,000 cases of COVID within the schools and very few transmissions within the schools or outbreaks, schools just did a wonderful job. I think what I'd focus on is, you know, for those who are 12 and older and are currently eligible for a vaccine that is the lowest age group between 12 and 17 for a vaccine uptake. And so if you look across New Hampshire only 58% of our total population is fully vaccinated amongst those 12 and older that are currently eligible, it's up to 66%. That's a good number, but that is very much distributed to the older age groups. And so, um, that is, you know, down [to] only around a quarter of eligible school-aged children, and we're at a point where to get fully vaccinated by the start of the school year, people need to begin to come out and get vaccinated now. So I'd say that's going to be a key thing. But for those who aren't eligible, yes, I would say that masks are going to be something that has to be discussed.

Rick Ganley: Well, let me ask you if there's any idea when we might see vaccine ages being lowered to that under-12 group?

Michael Calderwood: I don't think it will be by the start of the school year. I think my hope is that we will begin to get guidance on that in the fall. But we are going to have a group of children, those under the age of 12, will not be eligible, by the start of the school year. And so that's where these discussions are going to have to play out about what is the local community prevalence of this virus and are masks a part of what is needed to keep everyone safe?

Rick Ganley: Okay. Quick, last question here for Dr. Chan. Laura from Claremont asks, will booster shots be necessary for those who have been vaccinated?

Ben Chan: Great question. This is actually being discussed actively by the ACIP, the CDCs advisory committee. The science is still developing on this. I think it's very likely that there are some groups where booster doses will be needed or recommended. For example, people that are immunocompromised. It may not amount [to a] full immune response for the first full series. Whether everybody needs a booster dose, I think still remains to be seen. We still have not seen good, solid data suggesting waning of immunity over time, but that's something that's actively being studied as these vaccines get rolled out.

Mary McIntyre is a senior producer at NHPR.
For many radio listeners throughout New Hampshire, Rick Ganley is the first voice they hear each weekday morning, bringing them up to speed on news developments overnight and starting their day off with the latest information.
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