Silver Bullet July 8 - Variant roundup, a virus-fighting virus, zoo animals get vaccinated
A weekly update on all things COVID-19. News, public health guidance, trends, breakthroughs, and thousands of scientific papers distilled down to what you need to know right now.
Keeping track of variants
The Delta variant of the SARS-CoV-2 virus (B.1.617.2), which fueled India’s devastating winter/spring surge, now comprises more than half (51.7%) of all COVID-19 cases in the US, according to the CDC. Delta is more transmissible than the original strain of SARS-CoV-2, and causes more severe disease. It is quickly becoming the dominant strain of the virus in the US. States with low rates of COVID-19 vaccination are being hit hardest, and virologists say that spread among unvaccinated individuals raises the risk the more dangerous strains may emerge, particularly strains resistant to vaccines. Currently, vaccines available in the US are highly effective against the Delta strain (new results for JnJ). However, the fear is that with further mutations, vaccinated people will become vulnerable to infection again, restarting a new cycle of outbreaks.
Meanwhile, health officials in India are investigating a new variant, Delta Plus, that they believe spreads more easily, binds more easily to lung cells, and is potentially resistant to monoclonal antibody therapy. More data is needed to confirm the variant’s properties. BBC reports that the move to label Delta Plus a variant of concern has drawn criticism because far too few patients with it have been studied.
Public Health England is also monitoring the Lambda variant, which it designated a “variant under investigation.” Lambda was first found in Peru and has spread to 26 countries. Six cases have been identified in the UK.
Another variant, Gamma (P.1), has taken hold in Washington state. Gamma emerged in Brazil, driving a major wave of infections last winter. According to a briefing by Washington’s state epidemiologist Scott Lindquist, Gamma is associated with higher hospitalizations and deaths than any other strain of COVID-19. It has been found in 17% of infections in the state, second to Alpha (B.1.1.7). Vaccines remain effective against Gamma.
Due partly to the Delta variant and partly to relaxation of pandemic restrictions in areas with inadequate levels of vaccination, US COVID-19 cases have begun to rise, after falling for many weeks. Cases are up 14% over the past two weeks. Hospitalizations fell by 2% and deaths declined 19% in the same period. Hospitalizations and deaths tend to lag behind changes in case rates by 2-3 weeks. States with the steepest percentage increases include Arkansas (up 88% in 14 days with just 35% of its population fully vaccinated), Louisiana (up 85% with 35% fully vaccinated) and Mississippi (up 91%, with just 30% fully vaccinated). Populous states are logging the highest daily numbers. Florida is averaging 1493 daily cases, Texas 1333, and California 1285. Past hot spots New York and Michigan still have fairly low case numbers, but are seeing a slight uptick in percentage (2% and 11%, respectively).
Nearly all COVID deaths are now among unvaccinated people
An analysis of CDC data by the AP showed that almost all of the people in the US who died of COVID-19 in May 2021 were unvaccinated. Only 150 of those 18,000 deaths were among fully vaccinated individuals, or about 0.8%. Only 1200 of 107,000 COVID-19 hospitalizations in May were due to infections in fully vaccinated people, or about 1.1%. CDC Director Dr. Rochelle Walensky said, “nearly every death, especially among adults, due to COVID-19, is, at this point, entirely preventable.” US vaccination rates continue to climb slowly. As of July 8, 67.3% of Americans over 18 had received at least one shot. That number fell short of President Biden’s goal of 70% by the July 4 holiday.
mRNA vaccines may lead to lifelong immunity
A new report from Washington University in St. Louis and Icahn School of Medicine in New York shows that the mRNA vaccines from Pfizer-BioNTech and Moderna trigger immunity that may last for years. The findings suggest that boosters will not be needed unless the virus mutates significantly, and that immunity could even last a lifetime, especially in people who survived COVID-19 before being vaccinated. The researchers studied how the body produces memory B cells. These are cells that produce antibodies on demand whenever the body encounters a pathogen in its “library.” The cells are produced in a germinal center within the lymph node. Typically, they hit peak production of B cells around two weeks after a standard vaccination. However, in people vaccinated with these COVID-19 vaccines, the germinal centers were still pumping out cells 15 weeks later, with little or no decline compared to three, four, five, and seven weeks after vaccination.
WHO recommends arthritis drugs for severe COVID-19
The World Health Organization has updated its guidelines for treatment of COVID-19 to include a “strong” recommendation for the use of arthritis drugs tocilizumab and sarilumab in patients with severe or critical COVID-19. In a new publication in JAMA, WHO details results of a meta-analysis showing a 22% reduction in mortality for the drugs compared to usual care or placebo in hospitalized patients with COVID-19.
Metabolic activators reduce recovery time
Swedish and British researchers reported that when patients with COVID-19 were treated with a cocktail of metabolic activating supplements—nicotinamide riboside, L-serine, N-acetyl-L-cysteine, and L-carnitine tartrate, their recovery time was reduced by up to 3.5 days. The randomized, placebo-controlled, double-blind Phase 3 clinical trial was carried out in 309 outpatients in Turkey. Patients received the supplements twice a day for 14 days. Says the study’s lead author, Adil Mardinoglu, “Dysfunctional mitochondria have been implicated in worsened progression for Covid-19, and we are pleased to find that the combination of these metabolic activators helps to remedy the stress put on the body of an infected patient."
Benefits outweigh myocarditis risks for mRNA vaccines
According to data from the Vaccine Adverse Event Reporting System (VAERS), there were 484 preliminary reports of myocarditis or pericarditis associated with COVID-19 vaccination in people 29 and under through June 11. Of those, 79% made a full recovery, while 9 were still hospitalized and two were in the ICU. Myocarditis cases were higher than would be expected in the general population. For example, between 1-12 would occur in the same time period in people age 12-17, but 132 were observed. A committee of vaccine advisors to the CDC said that because these events are rare and largely mild, the benefits of vaccination still outweigh the risks. The FDA will include a warning about myocarditis and pericarditis to its information on the vaccines. Some of the most serious complications of COVID-19 itself include heart inflammation, particularly myocarditis.
CureVac vaccine disappoints in final clinical readout
The German biotech firm CureVac reported that its mRNA vaccine, CVnCoV, was only 48% effective in a final analysis of its late stage clinical trial in 40,000 volunteers in Europe and Latin America. For people below 60, the efficacy jumped to 77% for preventing moderate to severe COVID-19. The European Medicines Agency had set the bar at 50% efficacy for approval, however, the company has sent its data to the agency in the hope that it will see value in a vaccine with strong protection for younger people.
A virus-fighting virus
Researchers from Pennsylvania are developing a synthetic SARS-CoV-2 that fights SARS-CoV-2 by infecting the same cell and replicating much faster until both viruses are destroyed.
Viruses thrive by exploiting the cells they infect, but in order to replicate and infect other cells they must produce viral proteins. As a result, viruses are also susceptible to exploitation by defective versions of themselves that do not produce such proteins. A defective viral genome with deletions in protein-coding genes could still replicate in cells coinfected with full-length viruses. Such a defective genome could even replicate faster due to its shorter size, interfering with the replication of the virus. We have created a synthetic defective interfering version of SARS-CoV-2, the virus causing the Covid-19 pandemic, assembling parts of the viral genome that do not code for any functional protein but enable the genome to be replicated and packaged. This synthetic defective genome replicates three times faster than SARS-CoV-2 in coinfected cells, and interferes with it, reducing the viral load of infected cells by half in 24 hours. The synthetic genome is transmitted as efficiently as the full-length genome, suggesting the location of the putative packaging signal of SARS-CoV-2. A version of such a synthetic construct could be used as a self-promoting antiviral therapy: by enabling replication of the synthetic genome, the virus would promote its own demise.
Animals at Oakland Zoo get experimental COVID vaccine
Tigers, black bears, grizzly bears, mountain lions, and ferrets at the Oakland Zoo in California are getting doses of a new experimental vaccine authorized by the USDA. The vaccine was developed by Zoetis, which is donating more than 11,000 doses to nearly 70 zoos, plus conservatories, sanctuaries, universities, and government organizations in 27 states.
Pfizer and Moderna vaccines likely to produce lasting immunity, study finds, by Apoorva Mandavilli, The New York Times
‘I’m not vaccinated, but what’s the chance I’ll get COVID?’ by F. Perry Wilson, Medscape
Unvaccinated people are ‘variant factories,’ infectious disease expert says, by Maggie Fox, CNN