07/2023 Issue: What’s New This Month About Vaccines, Long-Covid, and More

A newsletter providing a short account of the articles published in the previous month.

Hello all! It’s time for me to send another monthly update on what has been published in Microbial Instincts, an independent publication about infectious diseases and vaccines, in June 2023. As usual, here is a short list (friend-linked) that I hope will keep you more scientifically informed:

Covid-19 vaccines

• Is Long-Vax Syndrome Real? I Performed A Meta-Analysis And Critical Literature Review To Find Out: Recent concerns have raised the possibility of vaccinated individuals developing long-Covid-like syndrome, i.e., long-Vax syndrome. In this long form, I delved into the literature to scrutinize the scientific validity of this syndrome, even performing a meta-analysis to gauge its incidence (Figure 1). In the end, I concluded that the current evidence on long-Vax syndrome is incredibly weak, and whether this syndrome is real or not depends on how you interpret the evidence and define this syndrome.
• New Booster Shots Are Coming, But Scientists Are Debating Who Should Get Them: Shinaa Kurisu provided an update on what to expect for the upcoming booster shot targeting the latest XBB class of SARS-CoV-2 variant. She further describes how different countries approach booster programs, ranging from offering boosters to all (e.g., Japan and the U.S.) to offering to only those over 50 years (e.g., EU countries).

Figure 1. Meta-analysis forest plot of pooled incidence of POTS among vaccinated individuals. Based on the random effect model of 0.000304 [95% CI of 0 to 0.002504], it means 30.4 cases per 100,000 vaccinated individuals or 0.0304% incidence, with a 95% CI of 0% to 0.25%. Since this 95% CI crossed 0%, it means that the pooled incidence is not statistically significant. Source: Shin Jie Yong.

Covid-19

• From Smell Loss to Sore Throat to Pink Eye: Is Covid Even Still Covid-19?: I described how Covid-19’s phenotype has evolved over the years — from the eerie disappearance of the sense of smell to sore throat and runny noses and then to peculiar pink eyes — by drawing on this biology. For instance, as SARS-CoV-2 transitioned from its original Wuhan variant to Delta and Omicron, its tropism for the olfactory support cells gradually decreased in favor of more upper airway localization (Figure 2), resulting in more sore throats and runny noses.

Figure 2. Left: Upon ACE2 binding, SARS-CoV-2 is activated by TMPRSS2, and the viral envelope fuses with the cell membrane. Right: Upon ACE2 binding, SARS-CoV-2 enters cells by endocytosis, and the spike protein is cleaved by cathepsin L. Omicron is more efficient at using the ACE2-cathepsin L endocytic route of cell infection rather than the usual ACE2-TMPSSR2 cell fusion route. And the upper airways have less TMPSSR2 than the lower airways. Source: Hoffmann & Pöhlmann (2022).

Long-Covid

• How to Reduce Your Risk of Long-COVID Realistically, According to Research: Herein, I described science-backed ways to reduce the risk of long-Covid. First, if you are young and have XY chromosomes (male), your risk is already lowered. But age and sex are non-modifiable factors. Thankfully, there’re modifiable factors that can mitigate the risk of long-Covid, such as regular exercise, avoiding smoking, getting metformin if caught Covid-19, and more. The more healthy lifestyle choices you follow, the lower your risk is (Figure 3).

Figure 3. The more healthy lifestyle factors pre-pandemic correlate proportionally with lower risk of long-Covid. Risk is adjusted for age, race and ethnicity, occupation, education, income, and medical comorbidities. Source: Wang et al. (2023).

Human papillomavirus (HPV)

• Multiple Oral Sex Partners: An Unspoken Risk for Throat Cancer: Shinaa Kurisu shed light on the surprising factor driving the surge in throat cancer among young adults — HPV infection from multiple oral sex partners. In fact, HPV is a known cause of cervical cancer, so it’s not surprising that it also promotes throat cancer. Kurisu then described how some countries are implementing broader HPV vaccinations — even to young males— to mitigate such throat cancer risk.

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