, coronavirus and other infectious diseases.

Rachel Lutz

The announcement of a $1 million payout in Ohio for those who received the COVID-19 vaccine did not seem to bolster vaccination rates in the state compared to elsewhere in the country, according to a 

Investigators from Boston University School of Medicine used US Centers for Disease Control and Prevention (CDC) COVID-19 Vaccine Tracker data in order to assess the changes in COVID-19 vaccination rates before and after the introduction of a lottery system plus the Food and Drug Administration's (FDA) Emergency Use Authorization for the Pfizer-BioNTech vaccine in children ages 12 to 15 years.The study authors explained that some states, like Ohio on May 12, 2021, introduced a system that would randomly pay up to $1 million to randomly-selected people who received the vaccine. Initial reports indicated that vaccine administration increased, so other states adopted similar lottery systems, the study authors noted. But they wanted to assess whether the lottery was responsible for the uptick in administration of the vaccines, or if it was due to eligibility expansion among children, which occurred at roughly the same time (May 10, 2021).

The study authors evaluated daily trends in adult vaccinations per 100,000 persons between April 15 and May 12, 2021 (defined as the pre-lottery period) and May 13 to June 9, 2021 (defined as the post-lottery announcement period). The investigators compared Ohio vaccination rates during those periods to countrywide vaccination rates during the same period.

From the start of the pre-lottery period to the end of the post-lottery announcement period, the investigators observed a drop in daily vaccination rates from 485 per 100,000 persons to 101 per 100,000 persons in the state of Ohio. This decline was also observed in other states around the country that did not introduce lottery incentives: 700 per 100,000 persons to 97 per 100,000 persons. The study authors also determined that Ohio and the country as a whole experienced a significant decline in daily vaccination rates before the May 12 lottery announcement.

After the lottery announcement was made, daily vaccination rates did not significantly increase in Ohio or the US, the study authors found. However, they added, the introduction of the lottery system produced a decline in the daily vaccination rate slowdown in Ohio and the US.

Before the lottery announcement, vaccination rates declined more rapidly around the country than in Ohio specifically, the study authors learned. And after the lottery system introduction on May 12, the vaccination rates in the US fell more slowly than the rates in Ohio, they also said.

“The study did not find evidence that a lottery-based incentive in Ohio was associated with increased rates of adult COVID-19 vaccinations,” the study authors wrote. “In contrast, the analyses suggest that the rate of decline in vaccinations slowed to a greater extent in the US than in Ohio after the May 12 lottery announcement.”

The study authors said this conclusion could possibly be attributed to the expanded eligibility criteria among adolescents, suggesting that the expansion of eligibility bolstered vaccination rates among adults. Their finding contrasts reports of increased vaccination rates in Ohio, the study authors said, and those reports did not consider adolescent vaccine administration.

“Further evidence supporting the effectiveness of lotteries as strategies for increasing vaccine uptake are needed prior to widespread and potentially costly adoption,” the study authors concluded.

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Before other states adopt randomly-selected payouts for COVID-19 vaccine administration, further research is needed into these lotteries’ effects on potential increases in vaccination rates.

Ohio COVID Vaccine Lottery Did Not Boost Vaccination Rates, Evidence Shows

Deploying treated mosquitoes designed to curb dengue fever was successful in reducing incidence in an Indonesia city by 77 percent, according to a 

Investigators from Indonesia conducted a cluster-randomized trial in order to test the efficacy of releasing 

 mosquitoes on the control of dengue in Yogyakarta, a city in Indonesia. 

 mosquitoes are the primary drivers of dengue, a mosquito-borne virus that can cause epidemics on multiyear intervals, the study authors explained.

The investigators added that a maternally inherited bacteria called 

 mosquitoes, but it can be introduced and used as a method of curbing dengue using the 

Mel strain. After getting approval from the leaders of 37 urban villages, the investigators randomly assigned 12 geographic clusters to receive deployments of the 

 mosquitoes and 12 clusters received no deployments.

In 2013, this research team found that these mosquitos were less likely than others to transmit dengue.

To assess the intervention, the study authors used a test-negative design and patients aged 3 to 45 years with acute fever who presented to local primary care clinics were recruited. The 8144 patients then underwent laboratory testing to virologically confirm dengue. Of the total patient group, 3721 lived in intervention clusters and 4423 lived in control clusters, the study authors found.

To be eligible, the participants also had to reside in the trial area every night for the 10 days preceding the onset of illness. If the participants had localizing symptoms linked to a specific diagnosis (such as diarrhea, otitis, or pneumonia) or were enrolled in the trial within the previous 4 weeks, they were excluded.

The study authors reported 4 cases of virologically confirmed chikungunya, and those patients were excluded. One patient came from the intervention cluster and 3 came from the control clusters. Additionally, the investigators noted, there were zero cases of Zika detected.

Virologically confirmed dengue was observed in 67 of 2905 participants in the intervention clusters (2.3 percent) compared to 318 of 3401 participants in the control clusters (9.4 percent), the study authors reported. Ultimately, the study authors calculated the protective efficacy of the 

 mosquitoes intervention was 77.1 percent. This rate was similar among 4 dengue virus serotypes, the study authors also added.

Hospitalization incidence for virologically confirmed dengue was lower among patients in intervention clusters when compared to control clusters as well: 0.4 percent vs. 3.0 percent, respectively. The study authors calculated this protective efficacy to be 86.2 percent. This lower incidence was found across all participant clinics, the study authors said. They also reported no participants died between enrollment and follow-up.

“It is reassuring that protective efficacy was observed against all 4 dengue serotypes and with the greatest confidence observed against DENV-2 and DENV-4, since these were the most prevalent serotypes,” the study authors wrote, adding that their findings in terms of efficacy are consistent with laboratory and field observations.

In the future, the investigators suggested, this method should be tested as a way to curb transmission of other diseases, such as Zika, chikungunya, yellow fever, and Mayaro viruses by 

Dengue epidemics can occur annually and are caused by specific mosquitoes, but introducing bacteria to the mosquitoes can reduce the transmission of the infection. 

Deploying Specialized Mosquitos Successfully Curbs Dengue Incidence

The introduction of the COVID-19 vaccine resulted in a decrease of COVID-19 cases, emergency department visits, hospital admissions, and deaths for older adults, according to the Centers for Disease Control and Prevention’s 

CDC investigators compared the rates of COVID-19 cases, emergency department visits, hospital admissions, and deaths during a period prior to vaccine introduction and during a period of time when vaccinations were ramping up in order to determine if those rates would be lowered due to increasing vaccination rates. The investigators compared November 29 to December 12, 2020 (the pre-vaccination period) to April 18 to May 1, 2021 (post-vaccination period) among the oldest age groups, such as those 70 years and over for hospital admissions, and 65 years and older for other measures.

The CDC calculated weekly proportion, rate and rate ratio by age to assess the differences by age for COVID-19 outcomes, they explained, including emergency department visits, hospital admissions, and deaths.

The vaccine was introduced to the U.S. on December 14, 2020 after the FDA employed an Emergency Use Authorization of the Pfizer-BioNTech vaccine. The peak 7-day average of vaccination distribution was 3.3 million doses per day in mid-April, the investigators noted, but decreased to 2.2 million by May 1. At the end of their analysis period, the CDC stated that 82 percent of adults aged over 65 years had received at least 1 vaccine dose. Among those 18 to 49, that number was 42 percent. By the end of the study period, the CDC said that 69 percent of those aged 65 or older and 26 percent of those aged 18 to 49 were fully vaccinated.

Emergency department visits peaked among all age groups during the week of January 3 to 9, 2021, but the study authors found that during the post-vaccination period, emergency department visits were 59 percent lower among all adults compared to the pre-vaccination period.

Rates of COVID-19 hospital admissions also peaked that same week, but post-vaccination rates were 63 percent lower than pre-vaccination rates, the authors learned. COVID-19 admissions were highest among the oldest age groups (70 years and older) but the proportion of adult hospital admissions for COVID-19 dropped from 45 percent pre-vaccine introduction to 27 percent during the post-vaccine period.

Peak mortality from COVID-19 was observed from January 3 to January 16, 2021 among all age groups, the study authors said. However, this decreased through May 1. The mortality rates were highest among the older age groups, but the study authors observed a decrease in the proportion of deaths from this group from 84 percent during the pre-vaccination period to 68 percent during the post-vaccination period. Among 18- to 49-year-olds, the rate of COVID-19 deaths decreased 66 percent, the study authors wrote.

“Despite sufficient vaccine supply and expanding eligibility, administration of COVID-19 vaccines has steadily declined in adults since mid-April 2021,” the study authors concluded. “These results suggest that tailored efforts by state and local jurisdictions to rapidly increase vaccine coverage among all eligible age groups could contribute to further reductions in COVID-19 cases and severe outcomes. Such efforts include effectively communicating the benefits of vaccination, ensuring equitable access and convenience, empowering trusted messengers, including primary health care providers, and engaging communities.”

Benefits were also observed among adults aged 18 to 49, with adults over 65 seeing the most benefit.

COVID Vaccine Introduction Results in Decreased Cases, Hospital Admissions and Deaths

People with HIV who are well-controlled using antiretroviral therapy (ART) can safely receive the AstraZeneca COVID-19 vaccine, according to a 

Investigators from the University of Oxford conducted a phase 2/3 trial of adults aged 18 to 55 years with HIV in order to understand and explore the safety and immunogenicity of the AstraZeneca AZD1222 (ChAdOx1) vaccine for people with HIV. The participants were eligible for the trial if they were on ART with undetectable plasma HIV viral loads, plus CD4 counts of more than 350 cells per μL between November 5 and 24, 2020. Then, the participants received 2 doses of the AstraZeneca COVID-19 vaccine, with the doses spaced 4 to 6 weeks apart. The investigators compared all outcomes to a control group with the same ages and dosing strategies as the HIV group.

All 54 of the study participants with HIV were male, the study authors noted, with most self-reporting as White. The median age was 42.5 years.

The HIV-negative cohort included 50 participants (26 males, 24 females), and the median age was 38.5 years. A majority of the HIV-negative cohort also self-reported as White, the study authors reported.

The study authors reported no serious adverse events among the participants, though local and systemic reactions occurred during the first 7 days after the first dose, including pain at the injection site, fatigue, headache, malaise, chills, muscle ache, joint pain, and nausea. The frequencies of these side effects occurred similarly between the HIV and non-HIV group, the study authors reported.

Antibodies against COVID-19 spike protein peaked at Day 42, according to the study authors, and were sustained until Day 56, which was 2 weeks after the second dose. The study authors added that they observed no correlation between the magnitude of the anti-spike IgG response at Day 56 and the CD4 cell count or age.

At Days 14 and 28, the study authors found no difference in response among the HIV-negative cohort, but said that the responses of HIV-positive patients were significantly higher by Days 42 and 56. Additionally, at Day 56, the study authors observed no correlation with antibody response and CD4 count or age, they said.

“These preliminary data show that the ChAdOx1 nCoV-19 vaccine given as prime-boost dosing given 4–6 weeks apart was well tolerated and produced equivalent immune responses in people living with HIV who are well controlled on ART compared with a similar adult population without HIV,” the study authors concluded, while noting that the study is ongoing. “These findings suggest that no dose adjustment in the vaccine is needed for people with HIV on ART with CD4 counts of more than 350 cells per μL.”

The study authors also noted that their sample size (54 participants with HIV) was too small to report protection from infection. However, the measured immunological response they observed matched the measured response to similar, larger studies of HIV-negative participants. And, in those larger studies, evidence has been mounting that vaccination leads to a reduction in symptomatic cases and hospital admissions, even among COVID-19 variants, they wrote.

“Our findings of robust immune responses to the ChAdOx1 nCoV-19 vaccine, irrespective of HIV status, are encouraging, and reinforce the message that people living with HIV should be supported to receive vaccination.”

AstraZeneca’s COVID-19 vaccine was safe and immunogenic for people with HIV who are well-controlled on antiretroviral therapy, a study has shown. 