Covid-19 new cases: By the numbers, good news, bad news

Surge in cases noted: What to know about the JN.1 variant and vaccine

Last updated:
Jay Hilotin, Senior Assistant Editor
3 MIN READ
Covid-19 strains are sweeping across some countries, with the JN.1 variant detected to show dominance in new reported cases. A fresh wave of infections is noted in South America  (Brazil) and Europe (UK). Singapore, Hong Kong, Thailand and China also reported a surge in new cases, amid the emergence of a new variant Covid-19 pathogen.
Covid-19 strains are sweeping across some countries, with the JN.1 variant detected to show dominance in new reported cases. A fresh wave of infections is noted in South America (Brazil) and Europe (UK). Singapore, Hong Kong, Thailand and China also reported a surge in new cases, amid the emergence of a new variant Covid-19 pathogen.
Bloomberg

It’s been more than 5 years since Covid was declared a pandemic. However, different parts of the world are still facing the regular emergence of new variants of the virus, SARS-CoV-2. 

In the last 28 days till April 27, nearly 25,500 new Covid-19 cases were reported to the World Health Organisation (WHO), led by Brazil and the UK.

In the first few days of May, a notable surge in new Covid-19 cases were seen rising in parts of Asia, including 14,000+ new cases in Singapore.

Governments are renewing calls for booster vaccinations and public health precautions.

What we know so far:

25,500
Number Covid-19 cases reported to the WHO in the last 28 days till April 27, 2025
7,300
New Covid-19 cases reported in Brazil (last 28 days till April 27)
5,500
New Covid-19 cases reported in the UK (last 28 days till April 27)

Covid-19 cases surge in Asia

Singapore

  • Covid-19 cases rose 28% to around 14,200 in the week ending May 3.

  • Hospital admissions increased by 30%, as per thee city-state's Ministry of Health (MOH) and Communicable Diseases Agency (CDA).

  • First time in nearly a year that official figures were released—signifying increased concern.

  • No new severe variants detected; waning immunity is seen as the main cause.

  • Government urging booster shots, especially for high-risk groups.

14,200
cases reported in Singapore in early May 2025 (from 11,000 at the end of April)


Hong Kong

  • Covid-19 situation is under renewed scrutiny.

  • Respiratory sample positivity rate is at its highest in over a year.

  • Wastewater surveillance shows a significant increase in "viral load".

  • The entertainment industry is impacted—singer Eason Chan cancelled a concert after contracting COVID-19.

  • An increase in respiratory samples testing positive for Covid-19 to 13.66% in the week ending on May 10 as compared to 6.21% four weeks prior.

  • Of the 81 severe cases reported (a 12 month high), 30 died, almost all of which were in elderly people with underlying health conditions.

China

  • Test positivity in hospitals has reportedly "more than doubled" in the five weeks before May 4.

  • This signals a potential new "wave" of infections.

  • The Chinese Center for Disease Control and Prevention (CDC) reported on May 8 that the Covid-19 "positivity rate" rose from 7.5% between March 30 and April 6 to 16.2% between May 4 and 10.

Thailand

  • COVID-19 resurgence followed the April Songkran festival.

  • Two major outbreaks occurred in recent months.

  • Authorities urging booster vaccinations, especially for vulnerable populations.

What explains the rise in cases

The rise in cases is likely due to waning immunity, say experts.

The good news: Though there's a spike in reported number of cases, an increase in severity has not been noted.

Bad news: Wastewater surveillance shows a significant increase in viral concentration, according to Hong Kong authorities. Moreover, JN.1 is harder to "neutralise" as existing immunity is "partially evaded", say experts.

About the JN.1 Variant

  • JN.1 is a subvariant of Omicron BA.2.86, first detected in late 2023.

  • Declared a “variant of interest” by WHO in December 2023.

  • Features about 30 "immune-escape mutations", more than other variants at the time.

  • JN.1 spreads more efficiently than BA.2.86 due to 1–2 additional mutations (as per Johns Hopkins University).

  • Continued vigilance and booster vaccinations are advised, especially in regions with rising cases.

Current dominant variants

  • LF.7 and NB.1.8 (descendants of JN.1) account for over two-thirds of sequenced cases in Singapore.

  • JN.1 is the dominant global variant, with prevalence in:

  • 93.9% of sequences in the Western Pacific Region

  • 94.7% in Europe

  • 93.2% in the Americas

  • 85.7% in South-East Asia

Symptoms of JN.1

  • Most cases are mild, especially in vaccinated or previously-infected individuals.

  • Common: sore throat, fever, cough, runny nose, fatigue, headache, loss of taste/smell

  • Occasional: conjunctivitis, diarrhea, vomiting

  • Severe: exhaustion, shortness of breath (requires medical attention)

Vaccine effectiveness

  • JN.1 is harder to neutralise, as existing immunity is partially evaded.

  • XBB.1.5 monovalent booster increases protection:

    • Provides 19 – 49% effectiveness against symptomatic JN.1 infection.

  • Booster vaccines available globally:

    • Pfizer-BioNTech Comirnaty (mRNA)

  • Moderna Spikevax (mRNA)

  • Novavax Nuvaxovid (protein-based)

  • Zapomeran (Kostaive) – self-amplifying mRNA (approved in Japan/EU)

  • Signs and Symptoms

    People with COVID-19 have a wide range of symptoms ranging from mild symptoms to severe illness.

    Symptoms may appear 2-14 days after exposure to the virus.

    Symptoms may start as mild, and some people will progress to more severe symptoms.

    The following list does not include all possible symptomsmay change (may allso change with new COVID-19 variants or depending on vaccination status:

    • Fever or chills

    • Cough

    • Shortness of breath or difficulty breathing

    • Sore throat

    • Congestion or runny nose

    • New loss of taste or smell

    • Fatigue

    • Muscle or body aches

    • Headache

    • Nausea or vomiting

    • Diarrhoea

    [Source: CDC]

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