Month: November 2021

Last week, the FDA authorized the Pfizer/BioNTech COVID vaccine for children ages 5 to 11. After conducting their own review, the CDC now recommends this vaccine for children in this age range, who can begin receiving their first dose within the week.

While many families have been eagerly awaiting the opportunity for their children to be immunized, others are hesitant. And most parents have questions about how COVID-19 affects younger children, vaccine safety in this age range, and whether the benefits outweigh potential risks. As a pediatric infectious disease specialist, I hear certain questions crop up repeatedly. Here’s what we know so far.

How does COVID-19 affect children in this age range?

While children continue to be much less likely than adults — especially adults 65 and older — to get severely ill from COVID-19, some children do get very sick. Thousands of children 5 to 11 have been hospitalized or need ICU-level support to recover from this infection. Almost 150 children in this age range have died from COVID-19. Additionally, over 5,000 cases of a serious inflammatory condition known as MIS-C that can follow COVID-19 infection have been reported. The majority of cases of MIS-C have occurred in children in this age range.

How has the Delta strain of the virus affected children?

The Delta strain of the virus that causes COVID spreads easily, particularly among people who haven’t received the vaccine. Children ages 5 to 11 remain more susceptible to infection, given their ineligibility to be vaccinated. In fact, more than one in five new cases recorded over the past two months while Delta infections surged in the US occurred in this age group, according to weekly reports from the American Academy of Pediatrics and the Children’s Hospital Association.

Can children spread the virus to others?

Several detailed reports describing outbreaks associated with settings such as summer camps, daycares, and schools, and those tracing transmission of COVID-19 within households, clearly demonstrate that children can spread this virus and infect others with whom they come into close contact.

Which COVID vaccines and doses are authorized for children ages 5 to 11?

Pfizer/BioNTech is the first COVID vaccine authorized by the FDA for this age group, based on results from a randomized controlled trial evaluating safety and immune responses. A separate trial launched by Moderna is being considered separately.

In a small number of children, the Pfizer/BioNTech trial compared three doses:

• 30 micrograms (the dose adults receive)
• 20 micrograms
• 10 micrograms.

This part of the trial showed that 10 micrograms, the smallest dose, resulted in fewer side effects while still generating robust immune responses similar to responses achieved with higher doses.

In the next part of the trial, more than 2,200 children ages 5 to 11 were randomly assigned to receive either a 10-microgram dose of the vaccine (two-thirds of participants) or a placebo dose (one-third of participants). All received two shots, spaced three weeks apart.

Those given the vaccine had similar immune responses as 16-to-25-year-olds who had received the full-dose series of two shots.

When Pfizer/BioNTech submitted data to the FDA, there were not many cases of symptomatic COVID-19 infections in trial participants. Out of 19 documented cases, most had received the placebo shots. Estimates suggest the efficacy rate of the vaccine is 90%. (Efficacy measures how much a vaccine reduces infection in a controlled trial.) Tests confirmed that the Delta viral strain had caused the infections.

What do we know about side effects for children this age?

Most children had no side effects other than pain at the injection site. Those who did have side effects most commonly experienced fatigue, headaches, and/or muscle aches after the second dose rather than the first dose. For example, only 6% of children had fever after the second vaccine dose. There were no cases of severe allergic reaction to the vaccine.

What is not yet known?

In very rare instances, the Pfizer/BioNTech COVID-19 vaccine is linked to myocarditis, which is an inflammation of the heart. When this occurs, it is mostly seen in young males following their second dose of an mRNA vaccine (Pfizer/BioNTech or Moderna). Most cases are mild, and children show no signs of long-term injury to the heart.

Among the 5-to-11-year-olds who received the Pfizer vaccine during the trial, there were no cases of myocarditis. However, this side effect is very rare and might not be noted until the number of children receiving the vaccine is much higher. The FDA and Pfizer/BioNTech will continue to closely monitor this age group for any occurrence of this rare side effect.

Can children get vaccinated against COVID-19 and influenza at the same time?

Yes. Children and adults can safely get both vaccines at the same time. The CDC urges everyone to get flu shots to help stay healthy during this flu season.

A randomized, controlled trial in the UK evaluated adults who received a flu shot or placebo shot in one arm and their second dose of the Pfizer/BioNTech vaccine in the other arm. The researchers reported in Preprints with The Lancet that side effects and immune responses were similar, whether the flu shot or a placebo shot was given at the same time as the COVID vaccine.

What other steps can parents take to protect children against COVID-19?

Parents should remember that an individual is not fully immunized and protected by the vaccine until 14 days after the second dose of the Pfizer vaccine. Masks are recommended for anyone who is unvaccinated, or not fully immunized, when indoors with people outside of their household. If rates of COVID-19 are high where you live, masks may be recommended indoors for vaccinated individuals as well.

Parents can continue to encourage other simple habits that help prevent colds, flu, and COVID-19, such as washing hands often, coughing or sneezing into an elbow, throwing away used tissues quickly, and avoiding crowded places and people who are ill when possible.

By 2050, 13.8 million people in the US will likely have Alzheimer’s disease, and two-thirds will be women. The economic cost is staggering, as it is estimated to rise to more than $2 trillion. Women are at the epicenter of this because the economic threat is especially dire for women, given they are an increasingly powerful element of our global economy and the vast majority of unpaid caregivers. Thus, maintaining intact memory starting early in midlife with the transition to menopause is critical not only for women themselves, but also for their families, society, and our economic health.

Preventing memory decline starts in early midlife

The decline in cognitive ability is not limited to neurodegenerative diseases like Alzheimer’s disease (AD), but also part of healthy aging, with consequences for our quality of life. Most studies of aging and cognitive decline, particularly studies of AD, begin in people in their 70s. However, understanding factors that happen earlier in life, and how they impact age-related brain changes, is critical for developing prevention strategies for one of the major public health challenges of our time.

What happens to women’s brains through the transition into menopause?

In addition to chronological aging, women undergo reproductive aging in early midlife: menopause, during which they experience a depletion over time of ovarian hormones such as estradiol, the primary form of estrogen that works in the brain. Our research team and others have demonstrated that estradiol directly relates to changes in memory performance and reorganization of our brain circuitry that regulates memory function. Thus, women and men undergo different aging processes, especially in early midlife when reproductive aging is more critical for women than chronological aging. However, cognitive aging is rarely considered a women’s health issue. This is essential, because viewing brain aging as beginning in early midlife, and understanding the impact of menopause on the brain, will allow for development of strategies to prevent memory loss for women.

On average, women perform better than men on measures of verbal memory, beginning as early as post-puberty. However, women’s advantage for verbal memory performance is reduced with menopause. Many women report increased forgetfulness and “brain fog” during the menopausal transition. All women eventually undergo menopause, but there is a large age range for when it begins (from late 40s to early 60s), and substantial variation in women’s experience of its impact.

Over the last 15 years, an increasing number of studies are mapping out the intricate ways in which menopause affects the brain and what helps maintain intact memory. For example, menopause can affect how brain cells are generated, connect with each other, and even die, and these processes impact brain regions that are critical for memory. Menopause also lowers the level of glucose in the brain, the primary fuel used by brain cells. The brain then looks to other metabolic sources to provide the necessary fuel to function — that is, the brain adapts to a new hormonal environment in order to maintain functioning.

Further, women with other medical conditions like diabetes and hypertension are at increased risk for cognitive decline. Research into understanding this is focusing, in part, on how the brain and body share similar processes to produce energy to function (metabolism), and how blood pressure and other aspects of the vascular system function similarly in the brain and body.

Can hormone replacement treatment help?

Research shows that timing matters. Initiation of hormone replacement (HR) in perimenopause (roughly four to eight years before menopause) or early menopause may have positive effects on brain activity and memory function, although systematic HR trials have not been conducted during perimenopause. Initiation of HR in late menopause may have adverse effects on the brain, and increase risk of disorders like Alzheimer’s disease. Research is critically needed to establish the most effective timing of administration, hormonal formula, dose, route of administration (for example, orally or by skin patch), and duration.

Further, to date much of the HR research has been conducted in healthy women, and little is known about its impact in women with chronic diseases such as diabetes and hypertension. Finally, there may be differences in responses in women who are genetically at high risk for brain disorders, like AD, that show increased benefits for using HR. Research shows us that one size does not fit all, and precision medicine is needed to identify which women may benefit the most. One example is for women with bilateral removal of the ovaries, particularly at a young age, for whom HR has been found to be very beneficial for brain function. In some women HR may not be an option, and alternative mechanisms may need to be identified, such as targeting levels of glucose and other effects associated with estradiol regulation of the brain.

What can women do to maintain brain health?

There are three major pillars for maintaining intact memory: effortful physical activity, effortful cognitive activity, and social contact. Research shows that the first two of these have direct beneficial effects on the brain, even at the level of cellular function. Social contact is another form of keeping our brains active by external stimuli, novel experiences, and perspectives outside of ourselves. Dietary habits (such as the Mediterranean diet, or intake of omega-3 fatty acids like in fish oil) have also had beneficial effects on memory function. The good news is that these are modifiable lifestyle habits, which may be particularly important for women with hypertension or diabetes who are at higher risk for cognitive decline.

Finally, adequate sleep (currently suggested as seven hours a night) is critical for brain health. Research has shown that during certain periods of sleep, learning is consolidated; that is, sleep plays a key role in storing and maintaining what we learned during the day, and even helps in clearing the brain of amyloid, one of the markers of potential AD pathology. More research is required to fully understand the beneficial impacts of these modifiable lifestyle factors. However, the time to start incorporating them into your life is now.