Expanding and Returning Pandemic
[Publication date of latest article cited: July 11, 2023]
For decades scientists and science journalists predicted another pandemic. As people moved into more environments, and interacted with more animal species, then more different microorganisms infected people. The pathogens mutated. Those transmitted via air, body contact, and water spread through human populations. People prepared for a probable new pandemic (Bisen and Raghuvanshi; Davis; Doherty “Pandemics”; Drexler; Garrett; Institute of Medicine “Perspectives”; Osterholm, Olshaker; Quammen “Spillover”; Quammen “Breathless”; Quick; Scoones; Shah; Sipress; Wolfe).
In the first four months of the SARS-CoV-2 pandemic, most potentially exposed people lived in more technologically developed areas. They could protect themselves from the transmission routes described above: staying more than two meters from others; buying and using soap and disinfectants; defecating in effective modern toilet and sewer systems; and staying at home living on their savings. Infected people usually spread respiratory diseases locally to people near them, then flew in airplanes to other cities in highly developed nations, starting more outbreaks. So, people of middle and upper socio-economic statuses spread the disease multi-nationally. Then people in each local outbreak spread it to people of lower socio-economic statuses in highly developed and less developed nations.
Then people spread COVID-19 to billions of people in less technologically developed areas, who live in crowded slums, or small rural houses. Many must work and live every day in crowded conditions, can afford to buy only a little soap, must use leaking sewers or simple latrines, or defecate outside, and have access to only basic health information and care. These living conditions and actions could compel them to transmit these viruses to hundreds of millions, killing millions (Bisen and Raghuvanshi; Burki “Double threat”; Caruso, Freeman; Chotiner; Davis; Doherty “Pandemics”; Doherty “What have we learnt”; El-Sadr, Justman; Garrett; Hargreaves et al.; Hopman et al.; Osterholm, Olshaker; The Lancet “Redefining vulnerability”; The Lancet “COVID-19 in Latin America”; Malley, Malley; Quick; Shah; Wolfe). For example, in Chinese and Ecuador villages, SARS-CoV-2 RNA was in bathrooms, and people using pit latrines were seroconverted against SARS-CoV-2 more than people with closed flushing toilets (Del Brutto et al.“SARS-CoV-2 RNA”; Del Brutto et al. “Factors Associated”; Liu L, Hu J, et al. “Pit Latrines”).
In the early phase of the pandemic in the first half of 2020, different countries experienced different transmission rates, depending on long term factors of the population. Countries having large populations, more older people with chronic health problems, more poverty and malnutrition, more smoking, and less national economic and government development had worse epidemics then (Kim H, Apio C, et al.). Later, those emphasizing scientifically-guided non-pharmaceutical interventions tended to control COVID-19 better (Kim H, Apio C, et al.; Nkengasong et al.; Oliu-Barton et al.). These differences came from the strengths and weaknesses of nations’ health systems. For example, African nations controlled the epidemic by monitoring their peoples’ COVID-19 infections, informing people how to prevent transmission, sequencing SARS-CoV-2 genomes, and discovering new variants. But they could not produce enough vaccines, medical supplies, and personal protective equipment, and so depended on highly developed nations, who provided insufficient amounts (Happi, Nkengasong).
People in less developed communities had been improving their health, prosperity, education, and gender relations for decades. But his pandemic is impelling them to reduce treatment and prevention for other diseases, earn less money, study less, and push women and girls into menial work, resulting in deterioration of the Sustainable Development Goals indicators (Bill and Melinda Gates Foundation; Branswell; The Lancet Public Health “Will the COVID-19 pandemic threaten the SDGs”). This deterioration could make them less able to protect themselves from COVID-19, in downward vicious circles.
When the COVID-19 pandemic started, scientists raced to discover the pathogen, its origins, mutations, world-wide spread, and to develop transmission prevention methods including vaccines (Pennington; Quammen “Breathless”). After immunization caused the pandemic to subside in more developed communities, then people relaxed their restrictions and re-started work. SARS-CoV-2 will continue to circulate and sicken some people for years (Scudellari “The pandemic’s future”; Zhang S). The virus could return from the still infected people in more developed communities (Cyranowski), and unvaccinated people in developed countries. These viruses will also return from less-developed communities and nations, and transmit to millions of not-yet-exposed people in more developed communities (Lee E, Wada, et al.; Oliu-Barton et al.).
People will isolate most of the severe infected COVID-19 patients, or they will die before they infect many people. So, the SARS-CoV-2 infecting them will not transmit to others. This will eliminate those viruses from natural selection. Consequently, years in the future, some SARS-CoV-2 will probably mutate into forms causing mostly asymptomatic to moderate infections, like the many other coronaviruses and influenza viruses that infect millions each year (Christakis; Racaniello).
The development and use of vaccines reduced transmission in countries in which most people are immunized. But it will take years to produce enough vaccines to immunize almost all of the world’s people, and persuade people to accept the vaccines through vaccine diplomacy (Hotez). Until then, COVID-19 will continue spreading (The Lancet Microbe “COVID-19 vaccines: the pandemic will not end overnight”). After health systems vaccinated most people in some nations, many others declined vaccination, and SARS-CoV-2 spread mainly among those unvaccinated (Mandavilli “Reaching ‘Herd Immunity’ Is Unlikely“; Mazer). By 2022, most people world-wide had been infected, and developed partial immunity to previous variants, and less immunity to new variants (COVID-19 Forecasting Team). People will need to adapt surveillance, immunization, and treatment programs to fit the resulting ongoing, more stable transmission pattern, and fit the changing situations of specific populations (Cohen, Pulliam; El-Sadr et al.).
Before testing, immunization, or curative treatments were widely available, people’s use of social distancing and low-technology methods prevention reduced infections. People will continue to benefit from using masks, eye glasses, hand washing, ventilation, etc. (Spinelli et al.). Even in communities in which most are immunized, mutating SARS-CoV-2 is causing outbreaks. Nations and communities will probably not develop herd immunity. But, they have developed “herd resistance” (Hussain et al.) or “seasonal population immunity,” which is partial herd immunity to each new variant, until new variants arrive, moderately sickening even vaccinated or previously infected people. We will need to use non-pharmaceutical prevention methods, develop new vaccines for the new variants, and cope with the social and political controversies about them, for many years in the future (Gandhi; Haseltine; Yong “How the Pandemic Now Ends”).
This pandemic stressed public health and government systems (Goldenberg). We can learn how to fix these problems to improve preparation and responses to future outbreaks of this disease, and to future pandemics (Cable, et al.; Daszak et al.; Olsterholm, Olshaker “Chronicle”). For example, in hindsight, people some governments probably should have restricted people less than they did, and encouraged people to move more of their indoor work and activities to outdoors (Gandhi “Endemic”). No people will be safe from this and future pandemics until all are safe. So, all nations and communities will need to help each other control and manage this new disease as an integral part of controlling all health problems (Ghebreyesus; Skegg et al.; The Lancet Infectious Diseases “The COVID-19 Exit Strategy”).
Acknowledgements
The following people provided advice, ideas, and information technology work:
Stephanie Brodine, MD, MPH; Tatiana Xochitl Chavez, BS, MS; Angela de Joseph, CPT, PES; Rosa Grant, BA; G. Timothy Gross, PhD; Patricia Law, BS, ET; Frahmarie M. Libag, MLIS; Hala Madanat, PhD; Eyal Oren, PhD, MS; Eleanora Robbins, PhD; Jackie Sangsanoy-Heng; and Jiratithigan Sillapasuwan, PhD, RN, NP, MNS.
Declaration of Interests
The author declares no competing financial or personal interests.