This HIV/AIDS Specialist Explains Its Similarities — And Differences — To COVID-19 - Forbes | Canada News Media
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This HIV/AIDS Specialist Explains Its Similarities — And Differences — To COVID-19 – Forbes

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Few viruses have instilled as much fear as HIV. Although it was discovered nearly 40 years ago, we still do not have a vaccine or a cure. But the COVID-19 pandemic has rivaled that level of fear as researchers race to find a vaccine for SARS-CoV-2, the virus that causes this disease. The largest question at hand: will developing a vaccine prove to be just as vexing?

The answer to that question remains to be seen, but there may be a lot we can learn by comparing the two viruses. As we think about vaccine development, however, it’s important to remember that HIV and SARS-CoV-2 are very different viruses. They are transmitted differently. They replicate differently. They cause disease differently.

So how similar are HIV and SARS-CoV-2?

A few recent studies on the effects of HIV and SARS-CoV-2 indicate that they do have some similarities. Shanghai-based researchers provided evidence that SARS-CoV-2 can infect T lymphocytes, the same cells targeted by HIV. Other researchers have documented that individuals with severe COVID-19 may exhibit lymphopenia, or an atypically low number of lymphocytes in the blood. Likewise, HIV infection results in this abnormality, eventually causing the immunosuppression associated with AIDS. But these findings should not cause us to assume that SARS-CoV-2 is like HIV.

Let’s look first at the infection of T lymphocytes, or white blood cells. The authors of this report provide evidence that SARS-CoV-2 can infect certain white blood cells in a laboratory setting. They also noted that MERS-CoV, a virus closely related to SARS-CoV-2, can infect those same cells. Importantly, however, they noted that neither MERS-CoV nor SARS-CoV-2 demonstrated any ability to replicate in these cells. It appears that these viruses can enter the cells, but the infection is abortive. HIV, in contrast, replicates aggressively in white blood cells, with infected cells spewing out thousands of new viral particles.

What about the observed lymphopenia? In a study of individuals who died of COVID-19, researchers noted that the amount of lymphocytes in the blood decreased steadily during the course of disease. By contrast, other standard blood markers, like red blood cell counts, remained fairly constant. Does this observation mean that infection with SARS-CoV-2 leads to immunosuppression, like HIV? Not necessarily. The authors note that several[1]  factors could lead to the lymphopenia. Instead, they emphasized that monitoring lymphocyte levels in people with COVID-19 may be an effective and easy way for clinicians to predict disease severity.

Is there anything we can learn from HIV as we try to develop a vaccine?

Perhaps the most important lesson is that vaccine development can be tricky. At a very basic level, vaccination replicates a natural process by intentionally exposing the body to something that looks like a pathogen. The vaccine may be an inactivated or weakened form of the pathogen or a protein isolated from it. In response, the body produces antibodies and cytotoxic white blood cells that can effectively combat the real pathogen, should it ever enter the body.

HIV thwarts this seemingly simple process in several ways. First, HIV mutates rapidly, constantly changing its appearance and remaining a step ahead of any response produced by the body. Second, the HIV genome, upon entering a cell, integrates into the host cell’s genome, effectively making itself invisible to the host’s immune response. Third, HIV is not particularly immunogenic, meaning our bodies don’t naturally mount an efficient immune response to it. These attributes of HIV have frustrated all efforts to development of an effective vaccine.

Here is the good news: coronaviruses have a significantly lower spontaneous mutation rate than HIV. Preliminary data suggest that this property is true for SARS-CoV-2. We also know that the SARS-CoV-2 genome does not integrate into the genomes of infected cells. Finally, past research on coronaviruses indicates that humans mount a strong immune response to these viruses.

Unfortunately, there’s bad news too. Attempts to develop a vaccine against SARS-CoV-1 following the 2003 SARS outbreak were not successful. Several candidate vaccines were shown to be relatively effective when tested on animals. But, the vaccinated animals also exhibited a severe immunopathology – the vaccine appeared to have caused the animals’ immune systems to become hyperactive and cause greater damage to them. More recently, researchers similarly showed that a candidate vaccine against MERS-CoV provided protection to mice from the virus, but could also result in the same kind of severe damage by their immune systems.

What about the vaccines being developed?

Many candidate vaccines are in the pipeline for SARS-CoV-2, the virus that causes COVID-19. Several of them already have entered Phase I human trials. Indeed, trials involving an mRNA-based candidate vaccine developed by the biotech company Moderna began on March 16, 2020, less than three months after Chinese authorities reported the first cases of this emerging disease. Most likely, several of these candidates will induce a reasonable immune response. But will they be safe and effective? Only thorough testing and human trials will provide the answer to that important question.

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Canada to donate up to 200,000 vaccine doses to combat mpox outbreaks in Africa

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The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.

It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.

Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”

Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.

Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.

A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.

On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.

Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”

But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”

“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.

Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.

Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.

Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.

“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.

“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”

This report by The Canadian Press was first published Sept. 13, 2024.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.

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How many Nova Scotians are on the doctor wait-list? Number hit 160,000 in June

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HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.

The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.

Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.

“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”

The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.

A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.

Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.

“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.

Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.

The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.

“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.

This report by The Canadian Press was first published Sept. 11, 2024.

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Newfoundland and Labrador monitoring rise in whooping cough cases: medical officer

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ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.

Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.

Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.

Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.

The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.

“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.

Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.

Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.

Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.

A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.

This report by The Canadian Press was first published Sept. 10, 2024.

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