Interview Highlights: N.H. State Epidemiologists On Masks, Testing, & Vaccine News | New Hampshire Public Radio

Interview Highlights: N.H. State Epidemiologists On Masks, Testing, & Vaccine News

Nov 18, 2020

Sign on Ceres Bakery in Portsmouth earlier this year. Portsmouth, N.H., has since adopted a mask ordinance.
Credit Dan Tuohy / NHPR

As COVID-19 cases surge in New Hampshire, state epidemiologist Dr. Benjamin Chan and Dr. Elizabeth Talbot, infectious disease specialist at Dartmouth-Hitchcock Medical Center, continue to emphasize the importance of social distancing and wearing a mask or face covering to stop potential exposure to the virus. 

The Exchange interviewed them Wednesday. Here are some highlights of that conversation. You can listen to the full discussion here. 

The following excerpts were lightly edited for length and clarity. 

N.H. Infection Rates Are Lower Than Other States, But Are Going Up

 Dr. Chan: Our current seven-day average PCR test positivity rate stands at about 3.5 percent.

So compared to other locations around the U.S. that are 10-15 percent, that remains relatively low.

But if you look at the trajectory, of the trend of that and other numbers over the last several weeks, those are going up. Our test positivity rate used to be less than 1 percent, and now we’re at three and a half percent.

Despite No Statewide Mask Mandate, Epidemiologists Say That Masks Protect Others And Yourself

Dr. Chan: We continue to emphasize the importance of face masks, especially now when we're seeing all communities throughout the entire state and surrounding states that have substantial or very high levels of community transmission. 

We’ve always said, “my mask protects you,” but now we have data that says, “my mask protects us both.”

  Dr. Talbot: There’s an additional bit of data that shows that these masks are not only effective in preventing diseases from the wearer to the person in proximity, but the other way around as well.

We’ve always said, “my mask protects you,” but now we have data that says, “my mask protects us both.”

So I think if you weren’t motivated by protecting the people around you, I hope that you’ll still hear the benefit is beyond that.

It Matters Who You Test, And How You Test Them

 Dr. Chan: There is absolutely a role for doing population-based testing, even if somebody is asymptomatic. But you have to use the right test. 

Antigen tests are most accurate when used in people with symptoms. We’re seeing new data which suggests lower accuracy in people without symptoms.

So when it comes to testing or screening people that don’t have symptoms, we continue to recommend the PCR tests, which remain available across the state, and looking to target these antigen based tests more for people that have symptoms, which maximizes the benefit and minimizes the risk of false negatives or false positives.

Contact Tracing Becomes Less Effective As Community Spread Increases

Dr. Chan: As we get to such high widespread levels of community transmission, the effectiveness of contact tracing is diminished. And why do I say that?

Contact tracing is a containment strategy, right? We look to identify and track down and break chains of transmission. And when numbers are low and community transmission is low, we’re much more effective and able to contain the virus through contact tracing.

But when we get to such high levels of community transmission throughout the state, the effectiveness of using that as a primary strategy is greatly diminished.

COVID-19 Is Now Mainly Spreading Through Small Household Gatherings

  Dr. Talbot: What we know of the rising rates, and now the rising hospitalizations, and even the data that we have showing that deaths are increasing and ICU adminissions are going up... all metrics are not favorable right now for having a gathering in your home. 

And Some Good News: Vaccines Are Extremely Promising

 Dr. Talbot: Pfizer's vaccine has exceeded expectations. Even just this morning, they updated  that their vaccine went from 90 percent efficacy to 95 percent efficacy, so that's great news. 

Nothing looks dangerous about this vaccine in the tens of thousands of people who have now received it.

This is the first time the vaccine technology has been demonstrated to be effective in humans, and I think the consistency of these numbers between Pfizer and Moderna (another vaccine trial), gives me greater confidence that the likely reality is that this technology works. 

I love what they’ve done in terms of making sure they’ve included racially and ethnically diverse populations and those who are most likely to get sick and even die from this infection, and those who are older, those who have medical comorbidities.

Nothing looks dangerous about this vaccine in the tens of thousands of people who have now received it.

So If I'm High Risk, Should I Hold Off Visiting People For A Few More Months?

Dr. Talbot: It’s an intersection of who you are. That is, if you have a medical comorbidity, if you’re sick with diabetes or heart disease, if you’re older than 65, then I think the answer is no, that you need to embrace the virtual ways of celebrating this holiday