AstraZeneca cocktail trial fails as Nigeria gets another 3.92m vaccine doses
• Nigeria to receive second batch doses, reopens vaccination for first COVID-19 shots
• WHO, NPHCDA warn of third wave threat in Africa
• High exposure to malaria explains low COVID-19 cases, deaths
Vaccine maker, AstraZeneca, yesterday revealed it has hit a setback in trials of a treatment for COVID-19. The drug, made from a combination of two antibodies, failed its main goal to treat coronavirus symptoms in exposed patients, AstraZeneca said in a statement. The late-stage trial failed to provide evidence that its COVID-19 antibody therapy protected people who had contact with an infected person from the disease, a small setback in its efforts to find alternatives to vaccines.
A single dose of the AZD7442 long-acting antibody treatment wasn’t statistically more effective than a placebo in preventing symptomatic COVID-19 in the trial of 1,121 people in the United Kingdom (UK) and United States of America (USA). The antibody treatment is separate from AstraZeneca’s widely used coronavirus vaccine developed in partnership with the University of Oxford.
The treatment has been undergoing phase 3 or final clinical trials to assess its safety and efficacy.
AstraZeneca said that 1,121 unvaccinated adults had been exposed to an infected person as part of the trial. Treatment of AZD7442 reduced the risk of developing symptoms by only 33 per cent, which was “not statistically significant,” it added.
The study assessed whether the therapy, a cocktail of two types of antibodies, could prevent adults who had been exposed to the virus in the past eight days from developing COVID-19 symptoms. Experts say the results mean it might have been due to chance and not the therapy.
Of the 1,121 trial participants, all 18 or older and unvaccinated, two-thirds received AZD7442. Of those, 23 developed symptomatic COVID-19, compared with 17 cases in the smaller placebo group. The results failed to show statistically significant efficacy of preventing symptomatic COVID-19 after confirmed exposure, AstraZeneca said.
The company is nevertheless continuing trials to assess whether the drug can prevent COVID-19 or treat more severe symptoms, while its vaccine, which was developed with the University of Oxford, continues to face safety doubts.
“While this trial did not meet the primary endpoint against symptomatic illness, we are encouraged by the protection seen in the PCR negative participants following treatment with AZD7442,” AstraZeneca Executive Vice President, Mene Pangalos, said in a statement.
In a parallel analysis of the same AZD7442 phase-three trial data, the antibody combination showed to be 73 per cent effective in reducing the risk of symptomatic COVID-19 in people who tested negative for evidence of the virus at the time they were dosed with the drug. Though the primary goal was preventing symptomatic COVID-19 after confirmed exposure with an infected person, the company said the treatment could find use in people who aren’t well protected by the range of coronavirus vaccines, or who are unable or unwilling to take a vaccine.
The company is banking on further studies to revive the product’s fortunes. Five more trials are ongoing, testing the antibody cocktail as treatment or in prevention. The next one will likely be from a larger trial testing the product in people with a weakened immune system due to cancer or an organ transplant, who may not benefit from a vaccine.
The jab has been suspended in several European countries over reports of rare blood clots. A top official in the European Medicines Agency on Sunday suggested that it might be worth abandoning AstraZeneca’s coronavirus vaccine for all age groups where alternatives are available.
The Anglo-Swedish drugmaker, which has faced a rollercoaster of challenges with the rollout of its COVID-19 vaccine, is also developing new treatments and repurposing existing drugs to fight the virus.
AstraZeneca also said yesterday it was in talks with the U.S. government on “next steps” regarding a $205 million deal to supply up to 500,000 doses of AZD7442.
MEANWHILE, Nigeria will get 3.92 million doses of Oxford AstraZeneca vaccine from COVAX facility but through non-Indian sources by the end of July, just as the administration of the second dose of the vaccine in the country will end by June 25.
Consequently, the Federal Government has urged all Nigerians who received their first dose at least six weeks ago to visit the nearest vaccination site to receive their second dose, for full protection against COVID-19 on or before the deadline while plans are in place to resume first doses, which had been halted to save its supply for second doses.
Speaking at the weekly COVID-19 vaccination briefing yesterday in Abuja, Executive Director of the National Primary Healthcare Development Agency (NPHCDA), Dr Faisal Shuaib, said: “Anyone 18 years and above who has not been vaccinated should visit the nearest vaccination site for the first dose of the AstraZeneca vaccine. For such persons, their second dose will be due in 12 weeks and by then we would have received the next consignment of vaccines. As at Tuesday, Nigeria had administered 1,978,808 first doses of the COVID-19 vaccine and 680,345 second doses.
Shuaib revealed that the Mastercard Foundation has pledged to donate $1.3 billion for vaccines in Africa over the next three years in partnership with the Africa Centre for Disease Control and Prevention, stressing that this is one of the largest corporate donations of the pandemic globally.
According to him, “the goals of this cooperation are to strengthen Africa CDC’s capacity, support local vaccine manufacturing, procure vaccines for at least 50 million people and help deliver shots to millions more.”
Shuaib warned that there has been a rise in COVID-19 cases in many African countries recently and all Nigerians must continue to take precautions to prevent the spread even though the country recorded lower infection figure in more than a year. The World Health Organisation (WHO) has also warned that the threat of a third wave of COVID-19 is real and rising in the African region, including Nigeria.
WHO Country Representative in Nigeria, Dr Walter Mulombo, said Africa is heading towards a sad milestone and a looming third wave, with many African lives at stake. He noted that the COVID-19 cases on the continent will soon pass the five million mark and as at the last two weeks, Africa recorded a 53 per cent increase in cases compared with the previous fortnight.
According to him, five African countries – Democratic Republic of Congo, Namibia, South Africa, Uganda and Zambia are currently experiencing a resurgence. “A rapid rollout of COVID-19 vaccines is therefore important, while intensifying preventive measures.”
MEANWHILE, more reasons have emerged why the country has so far recorded low COVID-19 cases and deaths compared to other parts of the world. The results of ground-breaking research conducted by Malaria Consortium shows that low previous malaria exposure is associated with more severe symptoms of COVID-19 and adverse outcomes compared with high exposure to malaria.
Patients co-infected with malaria and COVID-19 tend to have a higher frequency of confusion and vomiting but co-infection was not detrimental to a patient’s outcome. The results were recently published in The Lancet.
Malaria causes significant morbidity and mortality with an estimated 229 million cases and 409,000 deaths reported globally in 2019 alone, with over 90 per cent of these in sub-Saharan Africa. The potential implications of any clinical interactions between COVID-19 and malaria infection is, therefore, a major public health concern in Africa, where the chances of co-infection is relatively high.
The objective of the study was to better characterise COVID-19 cases in a high malaria burden setting and to determine the prevalence and describe the clinical consequences of SARS-CoV-2 and malaria co-infection.
Senior Research Adviser at Malaria Consortium and co-author of this study, Jane Achan, said: “This is the first study to describe in detail what is potentially happening in terms of clinical interactions between malaria and COVID-19.
“Given the prevalence of malaria in sub-Saharan Africa, understanding the pathology of what this means for patient outcomes is of huge importance. Modelling done at the start of the pandemic predicted the potential consequences of COVID-19 on malaria deaths due to interrupted interventions, but little is known about the impact of co-infection on morbidity and mortality. It was important for us to be able to rapidly respond to a global need and contribute to better understanding of the pathogenesis and relationship between the two diseases.”
The study, conducted between April and October 2020, analysed the results of 597 patients of all ages with a confirmed diagnosis of SARS-CoV-2 at COVID-19 treatment centres in eight tertiary hospitals across North, East, South and North-Western regions of Uganda. To determine the level of malaria exposure in patients, the research measured the level of immune response to components of the malaria parasite (P. falciparum) at time of hospitalisation. A very strong immune response indicates high previous exposure to malaria either recently or over time and low or no evidence of a response indicates low previous exposure to malaria.
The proportion of patients with low previous exposure to malaria suffering severe or critical COVID-19 was 30.2 per cent compared to only 5.4 percent of those with high previous exposure. The impact of low malaria exposure on the severity of COVID-19 remained even in patients without co-morbidities.