Health Topics – Johns Hopkins Medicine Podcasts

Many vaccines require more than one dose to be effective in preventing disease, and Covid-19 is no exception. That’s according to Jonathan Zenilman, an infectious disease expert at Johns Hopkins.

Zenilman: We do know that the boosts, actually at several different dosing levels, provide exponential increases in antibody levels. The framework is are these really boosters or is the true schedule of the vaccine something that should be 0,1, and six months, very similar to other vaccines that we use. And actually was the problem that because of the pandemic they really needed accelerated schedules?  :28

Zenilman says that as global criticism mounts against providing third doses on a routine basis when so many people haven’t had even one dose, it’s worth considering that the best protection against Covid-19 may very well be a three or more dose regimen. At Johns Hopkins, I’m Elizabeth Tracey.

Antibodies are proteins that circulate in the blood and act as first responders to viruses, hopefully warding off infection. Antibodies are produced either in response to immunization or natural infection, but whether they provide a useful measure of protection is unclear. That’s according to Stuart Ray, an infectious disease expert at Johns Hopkins.

Ray: There’s the formal question of whether the antibodies measure the thing that we’re trying to detect. The other is whether there’s a correlation that’s useful, and whether we can identify people at risk in a reliable way. Neutralizing antibody assays can measure something but we don’t know exactly where the threshold is for protection. We can try to make some inferences but even that estimate, with the best estimates we have, is imperfect. But both because we don’t exactly know what level and we’re only measuring one particular function, there’s lots of reasons why there’s uncertainty.  :29

Ray says attempts to use neutralizing antibody levels against Covid-19 are a case in point for this uncertainty. At Johns Hopkins, I’m Elizabeth Tracey.

The EU and many other high income countries are turning increasingly toward booster shots for Covid-19, at least for some groups of people. Mark Sulkowski, an infectious disease expert at Johns Hopkins, explains some of the data.

Sulkowski: Israel was a country was there was a high and early uptake in vaccine in nearly 80% of adults were vaccinated. The delta variant emerged and there was a high case rate and hospitalization rate among vaccinated individuals. That prompted a third dose for persons 60 or older greater than or equal to five months since full vaccination. On Med Archive is this report, suggesting the estimated what they called ‘booster protection’ for individuals who received a third dose. The end of this was in August so it wasn’t a long period of follow up time. And this study has generated a lot of controversy.  :35

Sulkowski says the controversy stems from the short follow up time and notes that much of the world’s population still doesn’t have a first dose even as others are now moving to third shots. At Johns Hopkins, I’m Elizabeth Tracey.

Shedding virus is the term used to describe the state of being infectious to others, and with Covid-19 there’s a lot about this state we still don’t know. Anna Durbin, an infectious disease expert at Johns Hopkins, says the picture is even more complicated when someone who is vaccinated becomes infected.

Durbin: This is viral load by PCR and we don’t know how much of it is infectious. So that’s my first caveat. We could be measuring dead virus or virus bound to antibody but by and large the more virus you have the more likely you are to transmit, the more likely you are to be symptomatic which can lead to cough and other things that also improve transmission. And generally it could be also that you harbor the virus longer so I think there are several different factors and included in that is behavioral.  :31

Durbin says it is known that people who’ve been vaccinated generally experience less severe cases of Covid-19 but that they can infect others, but how long that period lasts is still being investigated, so for now, masks and physical distancing remain good ideas. At Johns Hopkins, I’m Elizabeth Tracey.

Alpha, Beta, Delta, and most recently Mu. Variants of Sars-CoV2 are constantly arising but only some of them reach the level where they are monitored. Stuart Ray, an infectious disease expert at Johns Hopkins, explains.

Ray: We see variants arising all the time. But occasionally a variant will have genetic features, that are features that have been associated with changes in variants that have become dominant. Those mutations of interest can qualify a variant as being a variant of interest. They become variants of concern when they spread enough to play a significant role in the epidemic. Some observations of increased transmissibility, partial evasion of immune responses and so that makes them variants of concern.  :29

The World Health Organization developed the naming convention for Sars-CoV2 variants based on the Greek alphabet, which was welcomed by many because it simplifies communications about which ones are spreading most easily in different parts of the world, and may also help in developing vaccines. At Johns Hopkins, I’m Elizabeth Tracey.

The spread of the delta variant of Covid-19 may have reached a plateau in the United States, the most recent data suggest. Many have pointed to unvaccinated people as the primary driver of this latest surge. Mark Sulkowski, an infectious disease expert at Johns Hopkins, says optimism early in the summer contributed.

Sulkowski: One of the other factors was this return to normal activity. A poll taken in June where one out of three Americans thought we had turned the corner and optimism was reaching a peak – 89% of people were optimistic about the coronavirus situation- as they called it in the poll. Domestic and international travel, just a resurgence of travel as well, so people were getting back to normal activities, we went to reductions in mask wearing requirements and things like that, which are now reversed.  :31

Sulkowski says knowing the range of factors that helped the virus spread are informative in controlling it as well as helping people reduce their own risk. At Johns Hopkins, I’m Elizabeth Tracey.

Shutdown and transition to virtual school was tough on everyone, and now returning to school in person for many is also providing challenges. Jennifer Katzenstein, a child psychologist at Johns Hopkins, says this is all normal.

Katzenstein: (Jennifer) There’s a range of emotions as kids return to school, especially after virtual school for the length of time that they’ve been in virtual school. One of those may be relief, returning to the school setting, returning to their social interactions. But there also may be anxiety and worry, about returning to school with the demands of the school day. What I’m seeing, especially for our middle schoolers, is more uncertainty and anxiety, especially now that they’re changing classes. So for some of the kids going back to school is a big jump developmentally that can be causing anxiety and stress.  :29

Katzenstein says parents should try to be aware both of their children’s emotions as well as their own as we all accustom ourselves to the new routine. She advises seeking help if any issues seem to be worsening or if parents are feeling overwhelmed. At Johns Hopkins, I’m Elizabeth Tracey.

Covid-19 infection can be frightening for anyone, and now that kids are back in school many parents are more worried than ever. Aaron Milstone, a pediatric infectious disease expert at Johns Hopkins, says if parents are worried about a child’s symptoms they should not hesitate to reach out.

Milstone: I know one of the common questions I get is about what should be that threshold for parents to seek attention and go to their doctor. And I always tell parents if you’re worried it’s always okay to check in with your doctor. I mean there’s no harm in calling, scheduling an appointment and getting checked out. This year when kids have symptoms it’s equally important to get tested, cause we really need to know if kids have COVID so we can appropriately keep them away from their family members and other students, to keep their community safe.  :26

Milstone reminds parents that they really know their own child best, so when parents feel concerned it’s worth following up. Early recognition and management of a worsening condition is more likely to resolve well. At Johns Hopkins, I’m Elizabeth Tracey.

Mask or no mask? While for adults that may be a decision, most school districts around the country have opted in for this strategy to reduce Covid-19 transmission among their students. Aaron Milstone, a pediatric infectious disease expert at Johns Hopkins, comments.

Milstone: We’ve learned over time that masks really do help kids to stay in school. Not only are they going to prevent the spread of COVID virus this year, where we learned last year is they help prevent the spread of other respiratory viruses, like influenza, the common cold, even the illnesses that give kids vomiting and diarrhea in the winter. All those other viruses are equally disruptive for families so not only will masks help curb COVID spread but hopefully they’ll keep kids healthy this winter, and in school.  :26

Milstone points to soaring rates of infectious diseases like respiratory syncytial virus or RSV, around the country as masks and distancing have been relaxed or abandoned as evidence that these physical barriers have real benefits. He notes that parents may consider setting a good example by wearing mask also. At Johns Hopkins, I’m Elizabeth Tracey.

Now that most children are back in school, the majority of them in person, parents and kids need to continue their vigilance against becoming infected with COVID. Allison Agwu, a pediatric infectious diseases expert at Johns Hopkins, says that starts with masking up.

Agwu: Masks, masks and more masks, and I think even if masks are not being required really masking in schools and out of schools, to protect yourself, particularly in indoor spaces or where you can’t guarantee the distancing. Many schools are putting in distancing within the desks, the lunch, etc, and emphasizing the importance if your school doesn’t have that, of masking, distancing and making sure you’re being safe, a few schools don’t do that, most are, and talking to your kids about abiding by those rules for masking and distancing  .:27

Agwu notes that parents can help their kids by making sure they’ve got more than one mask on hand if one is soiled, and helping them run through strategies to avoid risking contagion in settings like sports or the cafeteria. She says parental support is critical. At Johns Hopkins, I’m Elizabeth Tracey.