Earlier this week, officials from the World Health Organization (WHO) issued a warning that COVID-19 "is still very much around us," noting a global increase in cases. 1
Dr. Maria Van Kerkhove, WHO's technical lead on COVID-19, stated, "Data from our surveillance system across 84 countries shows that the positivity rate for SARS-CoV-2 has been rising for several weeks." Recent widespread outbreaks have been reported in the Americas, Europe, and the Western Pacific during the summer months. Overall, the positivity rate is over 10%, with regional variations—such as in Europe, where it exceeds 20%. Remarkably, such high transmission rates during the summer months in the Northern Hemisphere are unusual for respiratory viruses, which typically spread more in colder temperatures. 2
In April, a group of new viral strains known as the FLiRT variant group (named after two of their mutations) began spreading, followed by a variant called LB.1 in June. These two variants, descendants of the JN.1 strain, are responsible for the current global COVID-19 cases. 3
In Vietnam, the Hai Duong Children's Hospital reported a significant increase in pediatric COVID-19 hospitalizations over the past month. Currently, the Infectious Diseases Department regularly treats 10–15 children with COVID-19 as inpatients. 4 Most hospitalized children are under one year old and have not been vaccinated. In Vietnam, COVID-19 vaccination is only recommended for children aged five and older. However, since June 2022, the U.S. FDA and CDC have authorized and recommended the Moderna and Pfizer-BioNTech vaccines for children aged six months to five years. 9 Other countries, like China, Hong Kong, Australia, Chile, Canada, and Cuba, have also implemented vaccination programs for children under five. 10, 11 Given the resurgence of COVID-19 and its impact on unvaccinated populations, Vietnamese health experts may consider allowing children aged six months to five years to receive the vaccine, following the example of other nations, to enhance their protection and reduce community spread.
Why is COVID-19 spreading so rapidly in the summer?
According to the U.S. CDC, COVID-19 activity tends to fluctuate seasonally. Data from four years of COVID-19 cases, hospitalizations, and deaths show that COVID-19 peaks in the winter (most recently in late December 2023 and early January 2024) but also in the summer (most recently in July and August 2023). Unlike influenza and respiratory syncytial virus (RSV), COVID-19 does not have a distinct seasonal pattern. 5
Three main reasons are believed to contribute to the widespread transmission of COVID-19:
The first reason is the change in human behavior during the summer. 8 As the weather warms, people spend more time indoors in air-conditioned spaces, where most virus transmission occurs. Closed windows to keep cool reduce ventilation, increasing the risk of virus spread. Additionally, people travel more and attend large events such as the Euro football championships or the Olympics. In these situations, people interact more closely, including those from areas with high COVID-19 cases or those with COVID-19 symptoms who mistakenly think they have the flu.
Moreover, the emergence of the new SARS-CoV-2 variant KP.2 (part of the FLIRT variant group) has shown high resistance to neutralization, meaning it can evade the immune system response generated by vaccines or previous infections. This increased vaccine resistance may partly explain the rise in COVID-19 cases caused by KP.2.6
Finally, the decline in COVID-19 vaccine booster uptake has also fueled the virus's spread. Van Kerkhove noted that WHO has observed a worrying decline in COVID-19 vaccination rates over the past two years, particularly among healthcare workers and people over 60—the two groups at the highest risk of severe illness. 7 This trend needs to be reversed immediately. After the robust global COVID-19 vaccination campaign in 2021–2022, most countries have not continued annual booster campaigns. Over time, the effectiveness of the last dose has waned, especially with the emergence of new variants.
What Can We Do to Protect Ourselves from COVID-19 This Summer and in the Upcoming Fall/Winter Season?
- Maintain personal hygiene and a clean living environment.
- Improve ventilation in your living space (open windows to allow air circulation).
- Continue wearing masks in public places.
- Avoid close contact with sick individuals, and stay home if you are unwell.
- Stay informed about the COVID-19 transmission levels in your area.
- High-risk individuals should receive COVID-19 vaccine boosters.
Compiled by: Nguyen Khanh Hang (email: nkh@vpha.org.vn)
Reference:
1. COVID still 'very much with us' with 20% of tests positive in Europe, WHO warns. Euronews. Accessed August 08, 2024. https://www.euronews.com/health/2024/08/07/covid-still-very-much-with-us-with-20-of-tests-positive-in-europe-who-warns
2. COVID-19 making worrying comeback WHO warns, amid summertime surge. United Nation. Accessed August 08, 2024. https://news.un.org/en/story/2024/08/1152866
3. KATHY KATELLA. 3 Things to Know About FLiRT and LB.1, the New Coronavirus Strains. Yale Medicine. Accessed August 08, 2024. https://www.yalemedicine.org/news/3-things-to-know-about-flirt-new-coronavirus-strains
4. Minh Khang. Hải Dương: Nhiều trẻ dưới 1 tuổi mắc Covid-19. Sài Gòn Giải Phóng Online. Accessed August 08, 2024. https://www.sggp.org.vn/hai-duong-nhieu-tre-duoi-1-tuoi-mac-covid-19-post752700.html
5. John Parkinson. COVID-19 Is Hitting Its Summer Surge. Infection Control Today. Accessed August 08, 2024. https://www.infectioncontroltoday.com/view/covid-19-is-hitting-its-summer-surge
6. Cảnh báo biến thể COVID-19 mới lây nhanh hơn, né miễn dịch tốt hơn. Thông Tấn Xã Việt Nam. Accessed August 08, 2024. Accessed August 08, 2024. https://tuoitre.vn/canh-bao-bien-the-covid-19-moi-lay-nhanh-hon-ne-mien-dich-tot-hon-20240506144518816.htm
7. WHO warns about rising COVID-19 cases globally amid 'alarming decline' in vaccine coverage. Anadolu Agency. Accessed August 08, 2024. https://www.aa.com.tr/en/latest-on-coronavirus-outbreak/who-warns-about-rising-covid-19-cases-globally-amid-alarming-decline-in-vaccine-coverage/3296579
8. Why COVID Surges in the Summer. Johns Hopkins Bloomberg School of Public Health. Accessed August 16th,2024 https://publichealth.jhu.edu/2024/why-covid-cases-rise-every-summer
9. CDC Recommends COVID-19 Vaccines for Young Children. Centers for Disease Control and Prevention. Accessed August 18, 2024. https://www.cdc.gov/media/releases/2022/s0618-children-vaccine.html
10. The 7 countries where kids under 5 years old are eligible for COVID-19 vaccines, and how the roll-outs are shaping up. The Bussiness Insider. Accessed August 18, 2024. https://www.businessinsider.com/countries-where-kids-under-5-getting-covid-19-vaccines-2022-4
11. Tiêm phòng chống COVID-19 cho trẻ em. Chính phủ Canana. Accessed August 18, 2024. https://www.canada.ca/content/dam/phac-aspc/documents/services/publications/diseases-conditions/covid-19-get-facts-vaccinating-children/facts-covid-19-vaccine-children-vie.pdf