Study: US vaccination program averted 1.1 million deaths

Researchers updated a Commonwealth Fund study yesterday, and now estimate that COVID-19 vaccination has prevented 1.1 million US deaths and 10.3 million hospitalizations, up from July's figure of 279,000 deaths and 1.25 million hospitalizations prevented.

Without the US vaccination program, COVID-19 deaths would have been approximately 3.2 times higher and COVID-19 hospitalizations approximately 4.9 times higher than the actual toll during 2021, Commonwealth Fund researchers said.

The numbers come as the nation hits the grim milestone of 800,000 dead from the novel coronavirus this week and faces new challenges from the Omicron variant.

Today an average of about 1,000 Americans are dying daily from the disease. The record daily death toll was seen in January 2021, with more than 4,000 deaths per day. That number could have been as high as 21,000 per day, if vaccines did not exist, and would have peaked 6 months after the winter surge seen last year, the authors said.

"The majority of these averted deaths and hospitalizations would have occurred during the late summer and early autumn, as the highly contagious Delta variant began to surge in southern states and spread to other parts of the U.S.," the authors said.
Dec 14 Commonwealth Fund report

Asymptomatic COVID-19 infections common, finds global review of studies

A systematic review and meta-analysis yesterday in JAMA Network Open finds that the rates of asymptomatic (symptom-free) COVID-19 among nearly 30 million people was 0.25% among those undergoing screening and 40.50% among those with a confirmed case.

On Feb 4, 2021, researchers from Peking University in Beijing reviewed 95 studies from around the world involving 29,776,306 people, 11,516 of whom had asymptomatic infections at screening. Of 19,884 patients with confirmed infections; 11,069 were asymptomatic. Twenty-one studies were published in June 2020 or before, and 74 were published after.

Asymptomatic COVID-19 cases are insidious because affected people aren't diagnosed because they don't seek medical care, can't be identified through temperature screening, and can spread the virus without knowing it.

The pooled percentage of asymptomatic infections was 0.25% among those screened but was higher in nursing home residents or staff (4.52%), air or cruise travelers (2.02%), and pregnant women (2.34%).

Among those with confirmed infections, the rate of asymptomatic cases was 40.50%, and was higher in pregnant women (54.11%), air or cruise travelers (52.91%), and nursing home residents or staff (47.53%). About one third of these cases were in healthcare workers or hospital patients. Asymptomatic COVID-19 infections were more common among those younger than 39 years than in older patients.

The study authors said that the high percentage of asymptomatic COVID-19 cases underscores the high risk of asymptomatic viral spread in communities. "This finding of a high percentage of asymptomatic infections among air or cruise travelers suggests that screening and quarantine on airport arrival is important for reducing community transmissions, especially in countries without local transmission," they wrote.

The researchers called for testing asymptomatic community members to prevent further COVID-19 transmission. "Screening for asymptomatic infection is required, especially for countries and regions that have successfully controlled SARS-CoV-2. Asymptomatic infections should be under management similar to that for confirmed infections, including isolating and contact tracing," they concluded.
Dec 14 JAMA Netw Open study

H5N6 avian flu infects 4 more in China

China has reported four more human H5N6 avian flu cases in two provinces, all involving people who were exposed to poultry before their symptoms began, Hong Kong's Centre for Health Protection (CHP) said today in a statement.

All of the patients are male, and one is a 3-year-old child. The rest are adults ages 49 to 58. Their illness onsets range from Nov 15 to Dec 4. Three are from Hunan province in the south central part of the country, including two from the city of Hengyang. The child is from Guangxi province in the south, near the border with Vietnam.

Three, including the child, were admitted to the hospital and are in serious condition. The other patient's infection is listed as mild.

The spurt of new cases reflects a dramatic uptick in China's H5N6 cases this year, with 31 reported so far. Since 2014 when the first human cases were detected, China has reported 57 cases, which are often severe or fatal.

The spike in cases has prompted global health groups to update their risk assessments. The CDC's latest assessment kept the risk as moderate and said sequencing data from recent samples found no evidence of increased adaptation to mammals or increased transmissibility.
Dec 15 CHP statement

WHO: Pakistan battling large dengue outbreak

Though dengue is endemic in Pakistan, the country is experiencing a large outbreak this year, with case numbers approaching the level seen in its last major outbreak in 2019, the World Health Organization (WHO) said yesterday in a statement.

Since January and through Nov 25, Pakistan has reported 48,906 dengue cases, including 183 deaths.

Punjab province has been hardest hit, accounting for roughly half of the cases. Other hot spots include Khyber Pakhtunkhwa and Sindh provinces.

The WHO said that, with Pakistan grappling with COVID-19 and a surge in dengue, the country faces a high risk of serious impacts from the latter. It notes that all four dengue serotypes circulate in various parts of the country, leading to a risk of reinfection and serious complications if the disease isn't treated promptly and effectively.
Dec 14 WHO outbreak notice