T cells induced by common colds help cross-protect against COVID-19
T cells induced by infection with coronaviruses such as those that cause the common cold might help protect against COVID-19, finds a small UK study today in Nature Communications.
Led by Imperial College London researchers, the study included 52 people exposed to SARS-CoV-2 through an infected household member. Participants underwent polymerase chain reaction (PCR) retesting 4 and 7 days after initial diagnosis starting in September 2020, before COVID-19 vaccines were widely available to most UK residents. Eighty-eight percent of participants were White.
Cross-reactive T cells were significantly more abundant in the 26 uninfected participants than in the 26 diagnosed as having COVID-19.
In an Imperial College London news release, first author Rhia Kundu, PhD, said that while T cells' cross-protective effect is an important discovery, "it is only one form of protection, and I would stress that no one should relay on this alone. Instead, the best way to protect yourself against COVID-19 is to be fully vaccinated, including getting your booster dose."
The authors said that the results could provide a blueprint for a universal vaccine to protect against infections from current and future SARS-CoV-2 variants, including Omicron (B.1.1.529).
Senior author Ajit Lalvani, MBBS, explained that T cells work by neutralizing proteins in SARS-CoV-2 rather than its surface spiked protein, the target of current COVID-19 vaccines. The T cells, he said, mutate much less often than the virus.
"Consequently, they are highly conserved between the various SARS-CoV-2 variants, including omicron," Lalvani said. "New vaccines that include these conserved, internal proteins would therefore induce broadly protective T cell responses that should protect against current and future SARS-CoV-2 variants."
Jan 10 Nat Commun study
Jan 10 Imperial College London news release
China reports another H5N6 avian flu case, plus H9N2 infection in a child
Following a sharp rise in human H5N6 avian flu cases last year, China reported its first illness involving the strain for 2022, Hong Kong's Centre for Health Protection (CHP) said today in a statement.
The patient is a 43-year-old woman from the city of Huizhou in Guangdong province. She is hospitalized in critical condition. The CHP reported didn't say how the woman likely contracted the virus.
Since 2014, China has reported 58 human H5N6 cases, which are often severe or fatal, including 31 in 2021. Laos is the only country outside China to report a human case. The virus has been detected in birds, however, in four Asian countries.
In other avian flu developments, China recently reported another H9N2 case, part of ongoing sporadic activity involving the strain. The patient is a 7-year-old boy from Heyuan City, also in Guangdong province, the European Centre for Disease Prevention and Control (ECDC) said in its latest weekly communicable disease outbreak report.
His symptoms began on Nov 28 after having contact with market poultry. His symptoms were mild. Since 1998, 95 lab-confirmed H9N2 cases have been reported from 8 countries, mostly from China. Illnesses are typically mild, with children as the most affected group.
Jan 10 CHP statement
Jan 8 ECDC weekly update
