The Manual is compiling some of the most significant news items regarding COVID-19 to help people stay up to date.
News items compiled by Richard B. Lynn, MD.
March 31, 2022
COVID-19 changes in the brain
Even patients with mild COVID-19 often have neurologic symptoms such as headache, loss of smell and taste, and memory problems. Sometimes these neurologic symptoms persist. It is unknown whether mild COVID-19 can cause changes in the brain that can be detected with imaging studies. A study from the UK examined brain imaging results in participants before and after COVID-19 and compared them with imaging studies in people who had not had COVID-19. The brain scans for the COVID-19 group were significantly different from those of the control group.
The infected participants also showed, on average, more memory problems (assessed with cognitive tests) between the two timepoints. Whether these effects can be partially reversed, or whether these effects will persist in the long term, remains to be determined.
March 15, 2022
COVID-19 vaccine effectiveness against omicron variant
Vaccine effectiveness against symptomatic COVID-19 disease caused by the omicron and delta variants after primary immunization and after a booster dose was studied in England and published in The New England Journal of Medicine on March 2, 2022. The study enrolled symptomatic people infected with the omicron variant, symptomatic people infected with the delta variant, and people who had eligible symptoms but tested negative for COVID-19. For all combinations of primary course and booster vaccines, vaccine effectiveness against symptomatic disease was higher for the delta variant than for the omicron variant. The authors concluded that booster doses of any vaccine resulted in a substantial increase in protection against mild infection. However, protection against symptomatic disease also decreases after booster doses.
March 2, 2022
COVID-19 and Pregnancy Complications
To evaluate the risk of serious complications in pregnant women with COVID-19 infections, researchers conducted a large study involving 14,104 pregnant and postpartum patients. The study enrolled women who delivered between March 1, 2020 and December 31, 2020 (with final follow-up continuing to February 11, 2021) at 17 US hospitals. All patients who tested positive for SARS-CoV-2 were included and compared with patients without a positive SARS-CoV-2 test result. The results of the study were published in the February 22, 2022 edition of JAMA. The primary outcome of the study was a composite of maternal death or serious morbidity related to hypertensive disorders of pregnancy, postpartum hemorrhage, or infection other than SARS-CoV-2. This primary outcome was significantly more likely in patients with SARS-CoV-2 infection than those without this infection. All 5 maternal deaths were in patients who were positive for SARS-CoV-2. Patients who had COVID-19 of moderate or higher severity were significantly more likely to have maternal death or severe complications of pregnancy. However, patients with mild or asymptomatic infection were not more likely to have serious complications. The authors concluded that among pregnant and postpartum women at 17 US hospitals, SARS-CoV-2 infection was associated with an increased risk for maternal mortality or serious morbidity due to obstetric complications.
February 14, 2022
Vitamin D and severity of COVID-19 infection
A study published February 3, 2022 in PLOS ONE looked at all patients admitted to a medical center in Israel between April 7, 2020 and February 4, 2021 who had positive polymerase chain reaction (PCR) tests for SARS-CoV-2 (the virus that causes COVID-19). Of the 1176 patients with a positive PCR test, 253 had their level of vitamin D measured within 2 years before the COVID-19 test. A lower vitamin D level was more common among patients with the severe or critical COVID-19 than among patients with mild or moderate disease. Patients with vitamin D deficiency were 14 times more likely to have severe or critical COVID-19 than patients without vitamin D deficiency. Pre-infection deficiency of vitamin D was associated with increased disease severity and death due to COVID-19. The authors suggested further study to determine whether supplementation with vitamin D for people in the community who have low vitamin D levels will impact the severity of future COVID-19 episodes.
February 2, 2022
Risk factors identified early in the course of COVID-19 may identify patients at risk of post-acute sequelae of COVID-19
Post-acute sequelae of COVID-19 (PASC) is what doctors call long COVID or long-haul COVID. the term describes long-term symptoms experienced weeks to months after primary infection with SARS-CoV-2, the virus that causes COVID-19. PASC is a common problem and represents an emerging global crisis. However, risk factors for PASC and their biological associations are poorly understood. A study published in the journal Cell in January 2022, reported on an investigation of 309 COVID-19 patients from the time of initial diagnosis through to convalescence 2 to 3 months after onset of initial symptoms. At this convalescence time, 52% of study participants reported fatigue, 25% had cough (25%), and 18% had loss of smell and taste.
The study combined clinical data with patient-reported symptoms. Researchers identified four characteristics that, if present at the time COVID-19 is diagnosed, increase the risk the person will have long-term symptoms. These risk factors are
Different patterns of these risk factors correlated with different PASC symptoms. Although additional studies are needed to determine just how valuable these factors are in predicting long-term COVID symptoms, their presence at diagnosis allows doctors to begin to identify patients at risk and start planning treatment.
January 20, 2022
Multisystem inflammatory syndrome in children
Multisystem inflammatory syndrome in children (MIS-C) is a rare but important complication of COVID-19. Although most children with COVID-19 have mild or no symptoms, some children can have severe illness. The current increase in the number of children with COVID-19 being admitted to hospitals in the United States makes MIS-C even more important. The CDC established a national reporting system to gather data about patients suspected of having MIS-C. An analysis of this database was published in April 2021 in the medical journal JAMA Pediatrics.
The analysis included 1733 patients with MIS-C. Almost 60% were male, and 71% were Hispanic or Black. More than half had gastrointestinal symptoms, rash, or redness of the eyes. Low blood pressure or shock and heart problems, including myocarditis (inflammation of the muscle tissue of the heart), were common among affected children. Overall, about 60% of affected children were admitted to the intensive care unit, and 24 patients died. The first 2 MIS-C peaks followed COVID-19 peaks by 2 to 5 weeks. This finding suggests that MIS-C is due to a delayed immunologic response to infection with SARS-CoV-2 (the virus that causes COVID-19).
January 4, 2022
Omicron severity in the UK
A report by the UK Health Security Agency (UKHSA) regarding COVID-19 variants published on Dec. 31, 2021 provided insight into the severity of Omicron cases compared to Delta cases. The analysis included 528,176 Omicron cases and 573,012 Delta cases occurring between November 22 and December 26, 2021. The risk of presentation to emergency care or hospital admission with Omicron was approximately half of that for Delta. The risk of hospitalization alone with Omicron was one-third of that for Delta. These preliminary data may be affected by delays in reporting hospitalization. Overall, the data suggest that infection with Omicron causes less severe disease than infection with Delta in individual patients. The report emphasizes that this may not result in a lower burden on hospitals given the higher transmission rate with Omicron.
The analysis evaluated possible risk factors for hospital admission, including vaccination status. Researchers found that the risk of being admitted to hospital for Omicron cases was 65% lower for patients who had received 2 doses of a vaccine and 81% lower for those who had received 3 doses of vaccine compared to those who were unvaccinated (including those < 28 days since their first vaccine dose).
December 7, 2021
Omicron variant has unique insertion mutation
The virus that causes COVID-19 (the SARS-CoV-2 virus) is one of 7 coronaviruses that are known to cause disease in humans. Four of these are seasonal coronaviruses that most frequently cause symptoms of the common cold. Three cause much more severe, and sometimes fatal, respiratory infections (severe acute respiratory syndrome [SARS], Middle East respiratory syndrome [MERS], and COVID-19).
Researchers are busy studying the Omicron variant of SARS-CoV-2. They have discovered that the Omicron variant has substitution and deletion mutations similar to those in previous SARS-CoV-2 lineages. In these types of mutations one bit of a chromosome is deleted or substituted for another one. However, researchers also identified an insertion mutation in the Omicron variant (in which a bit of additional genetic material is added to the virus gene) that has not been observed in any SARS-CoV-2 lineage other than Omicron. Importantly, this insertion mutation has been observed in a seasonal coronavirus (HCoV-229E). The authors theorize that this mutation in Omicron may have arisen in a patient coinfected with both the SARS-CoV-2 virus and HCoV-229E.
November 10, 2021
BNT162b2 COVID-19 vaccine in children 5 to 11 years old
The data from the clinical study on the Pfizer-BioNTech COVID-19 vaccine (mRNA) in children 5 to 11 years of age was published in the New England Journal of Medicine on November 9, 2021. Study participants received two doses of the vaccine 21 days apart. The dose was one-third the dose used in adults and children aged 12 and older. The COVID-19 vaccine was safe, effective, and able to induce an immune response in children 5 to 11 years of age.
Side effects were generally mild to moderate, lasting 1 to 2 days. Injection-site pain was the most common local reaction, occurring in about 74% of vaccine recipients. Fatigue and headache were the most frequently reported systemic reactions. Frequency of fatigue and headache was similar among vaccine and placebo recipients after the first dose but were more frequent among vaccine recipients after the second dose.
A significant immunological response was achieved by 99.2% of participants 1 month after the second dose (same immunological response rate as in vaccine recipients 16 to 25 years of age). There were 3 cases of COVID-19 (with onset 7 days or more after the second dose) among the 1,517 vaccine recipients and 16 among the 751 placebo recipients; the observed vaccine efficacy was 90.7%. No cases of severe COVID-19 or multisystem inflammatory syndrome (a rare complication of COVID-19 that causes fever, abdominal pain, and a rash) were reported.
October 28, 2021
Myocarditis after BNT162b2 messenger RNA vaccine in Israel
Data from an Israeli study on myocarditis after vaccination for COVID-19 was published in the New England Journal of Medicine on October 6, 2021. The study reviewed data obtained from December 20, 2020 to May 31, 2021, regarding all cases of myocarditis reported to the Israeli Ministry of Health. Myocarditis is inflammation of the muscle tissue of the heart. By May 31, 2021, approximately 5.1 million Israelis (of 9.3 million Israeli residents) had received two doses of the Pfizer vaccine. There were 283 cases of myocarditis reported. These cases included 142 that occurred among vaccinated persons within 21 days after the first dose or 30 days after the second dose, 40 among vaccinated persons not in proximity to vaccination, and 101 among unvaccinated persons. Of the cases of myocarditis occurring after vaccination, most occurred after the second dose and most cases most were mild.
In most people, myocarditis occurred after the second dose. Myocarditis after vaccination occurred most often in males between the ages of 16 and 19 years.
The authors concluded that the incidence of myocarditis was low but increased particularly after the receipt of the second dose of the Pfizer vaccine among young male recipients.
October 13, 2021
Residual symptoms seven months after COVID-19 in people treated as outpatients
Symptomatic people who tested positive for COVID-19 at the Geneva University Hospitals in Switzerland from March 18 to May 15, 2020, were contacted again at 30 to 45 days and 7 to 9 months from diagnosis and asked about symptoms consistent with COVID-19. This study was published in the Annals of Internal Medicine in September 2021. The follow-up at 7 to 9 months after COVID-19 diagnosis was completed by 410 patients, of whom 39.0% reported residual symptoms. Fatigue (20.7%) was the most common symptom reported, followed by loss of taste or smell (16.8%), shortness of breath (11.7%), and headache (10.0%). The authors concluded that about a third of persons with mild to moderate, acute COVID-19 in an outpatient setting have long-term symptoms at 7 to 9 months.
September 27, 2021
Efficacy of the BNT162b2 messenger RNA vaccine booster in Israel
The recent approval in the US of a third (booster) dose of the BNT162b2 messenger RNA vaccine (Pfizer–BioNTech) was based in part on the experience in Israel. In Israel, the administration of a third (booster) dose of the Pfizer vaccine was approved on July 30, 2021, for persons who were 60 years of age or older and who had received a second dose of vaccine at least 5 months earlier. A study published in the New England Journal of Medicine on September 15, 2021, reported on data collected from July 30 through August 31, 2021, regarding 1,137,804 Israeli residents who were 60 years of age or older and had been fully vaccinated (received two doses of the Pfizer vaccine) at least 5 months earlier. The rate of confirmed COVID-19 and the rate of severe illness were compared between those who had received a booster injection at least 12 days earlier and those who had not received a booster injection. The results showed that at least 12 days after the booster dose, the rate of confirmed infection was lower in the booster group than in the non-booster group by a factor of 11.3, and the rate of severe illness was lower by a factor of 19.5. The study concluded that the rates of confirmed COVID-19 and severe illness were substantially lower among those who received a booster (third) dose of the Pfizer vaccine.
September 13, 2021
Effectiveness of BNT162b2 messenger RNA vaccine in preventing SARS-CoV-2 infection in pregnant women in Israel
The Pfizer-BioNTech mRNA COVID-19 vaccine was approved based on clinical trials that excluded pregnant women. To learn about the effectiveness and safety of this vaccine in pregnant women, a retrospective cohort study, in which investigators looked at the number of COVID-19 infections that occurred in pregnant women who were vaccinated against SARS-CoV-2 and compared with the number of infections among pregnant women who were not vaccinated. Pregnant women vaccinated with a first dose from December 19, 2020, through February 28, 2021, were included. SARS-CoV-2 infection was defined as a positive PCR (polymerase chain reaction) test result obtained from nasopharyngeal swabs and included both asymptomatic and symptomatic patients. SARS-CoV-2 infections occurred in 118 vaccinated women and 202 unvaccinated women during a median follow-up of 37 days. The observed rate of SARS-CoV-2–related hospitalizations was 0.2% among the vaccinated group vs 0.3% among the unvaccinated group. There were no severe adverse events. There were no notable differences between the vaccinated and unvaccinated groups regarding preeclampsia, intrauterine growth restriction, infant birth weight, abortions (both spontaneous and induced), stillbirth, maternal death, or pulmonary embolism.