It has 66 per cent effectiveness overall and is expected to seek United States Food and Drug Administration approval this week. It is also a simple single shot that requires normal fridge storage.
Novavax, which is working on a double-dose vaccine, reported that it appears to be 89 per cent effective in a British study. It can also be stored in standard fridges.
These results probably amount to a preliminary pat on the back for the Government's approach of buying different types of vaccines, rather than putting its eggs in one basket.
There are international supply and distribution questions hanging over the other New Zealand-bound jabs. The European Union introduced tighter rules on exports of Covid-19 vaccines amid a row with AstraZeneca.
Unlike the world's dreary 2020, this year has been a mixed bag so far, with some hope for progress but also setbacks.
For instance, the good news over the new vaccines comes with a stormy lining.
Both the J & J and Novavax studies reported a drop in vaccine effectiveness in South African tests. US infectious disease expert Dr Anthony Fauci described that reduced protection as "really a wake-up call" and there was a need "to vaccinate as many people as we possibly can".
These two vaccines - unlike those first out last year - are being tested while new variants of the coronavirus are raging in Britain and South Africa, two countries New Zealand has close ties with.
The South African mutation appears to be the trickier of the two, and it is the variant that escaped from managed isolation here.
It's more evidence that while the world has been fortunate to develop exceptional vaccines so quickly, a major vaccine push needs to nail down that advantage before the variants become more widespread. And doses can only be one layer of protection, next to others such as wearing good-quality masks and testing.
The J & J vaccine was 72 per cent effective against moderate to severe cases in the US, compared with 66 per cent in Latin America and 57 per cent in South Africa.
Novavax said its interim British data suggested the jab is nearly 96 per cent effective against the older coronavirus and nearly 86 per cent effective against the UK variant.
In South Africa, a study included some volunteers with HIV. The Novavax vaccine was 60 per cent effective for those without HIV and provided 49 per cent protection overall. A third of the volunteers already had original virus antibodies and this did not protect them against the variant.
Pharma labs are applying themselves to creating vaccine fixes for the major mutants. Germany is ordering vaccines for 2022 in case regular or booster doses are needed because of variants.
The rise of the variants suggests that the coronavirus could be a problem for a long time regardless of our own vaccination programme this year.
To some extent we are reliant on the virus being brought under control everywhere. Otherwise we could see regular cycles of new variants, new outbreaks and new vaccine updates.