Covid 19 Delta outbreak: Ask us anything on Covid - September 2

Living in alert level 3 and 4 lockdown comes with a unique set of rules, some of which are not always clear. In our new daily feature we answer questions from readers about anything Covid-related. Email covidquestions@nzherald.co.nz

During the current outbreak I haven't seen any mention of the Bluetooth function in the Covid app pinging anybody to tell them that they have been near someone who subsequently tested positive. Have there been any detections via the Bluetooth function?
Ian F

On Saturday, the Ministry of Health told media fewer than 10 people had received a notification that they had come into contact with a positive case through use of the Bluetooth function on the NZ Covid Tracer app.

When questioned about the figure at the 1pm media conference on Sunday, director general of health Ashley Bloomfield said that may well be the case but he did not have data about it on hand.

"We have been using it where people have said they had Bluetooth turned on, then we've used that to send out messages.

"Because of the number of cases, it was not necessarily a question our contact tracers were asking at the first interview. We have given them a nudge around that.

"It seems from the demographic of most of our cases, many of them did not have Bluetooth turned on."

At the same media conference Prime Minister Jacinda Ardern said as of August 29, there had been 110 location alerts.

"It seems that the tracer app is being used but the Bluetooth function may not be used as often by those who are involved with our cases."

On Sunday, 1 News reported that notifications had been sent to more than 3900 devices which had been used to scan in at a location and time of interest since August 17.

Auckland University's Dr Andrew Chen has explained this week that when Bluetooth tracing is turned on it sends out a code, called a key, as you move around.

When your phone is physically close to another device with the function turned on the phones exchange keys which are recorded in a log in the app.

If someone with the Bluetooth function turned on tests positive, contact tracers can ask the person to upload the keys on their phone to a central database. Other devices using the function regularly scan the database and check them against their log.

If there is a match the user is notified through the app and asked to get a test. The Ministry of Health does not know the identity of those who have matched so it's up to individuals to follow the advice.

Chen said it was pretty similar to how the QR code system worked except with the QR code system contact tracers could still send out an exposure notification if the case wasn't using the app by looking up the ID for the location.

Is it possible to get a breakdown of how many new cases are household contacts? Then we get a better idea of the spread.
Jordan L

Of the 49 new cases reported on Tuesday, 57 per cent were household contacts - 28 people.

Of the 53 cases reported on Monday, 66 per cent were household contacts (35 people) and of the 83 cases reported on Sunday, 52 per cent were household contacts (43 people).

Of Tuesday's cases 25 per cent were considered to have been infectious in the community at any point. That compared to 23 per cent on Monday, 30 per cent of new cases on Sunday and 35 per cent of the cases reported on Saturday.

I spotted a story in the NZ Herald regarding the administration of saline solution instead of the Pfizer vaccine. I would love to know why there was even a saline solution?
Hipkins cites an accounting error as opposed to a case of botched vaccines - that makes no sense. And, 44 days with no comprehensive answer around why this has happened? Not good enough.
Anon

A vial of the Pfizer vaccine contains multiple doses. Once thawed the contents of the vial need to be diluted using saline solution to achieve the right concentration and dissolve all the particles in the concentrated vaccine.

The possible error at the Highbrook vaccination centre on July 12 was discovered because five doses remained at the end of the day which didn't tally up with records showing how many people had been vaccinated.

Covid 19 Response Minister Chris Hipkins said it was possible it could be an "accounting error" because some vaccinators may have been able to get six doses from a vial rather than five.

In theory, the amount of liquid in each vial once diluted equates to just over seven doses but in practicality it is impossible for vaccinators to measure out the 0.3ml dose that precisely. Even getting six doses out of a vial requires the use of a specific type of syringe which has not been widely used until now.

Hipkins has accepted there is also the possibility it was a botch-up.

As for it taking 44 days for anyone to be informed, Hipkins described it as "regrettable".

The Director General of Health Ashley Bloomfield said health officials had since been seeking advice on what the best solution to the situation was and they intended to let people know once a decision had been made.

What do people without cars do when they require a test? Is it safe for them to stand outdoors masked for hours? How do they join a queue if queues are in cars?
Donna H

Many community testing sites have walk-in facilities as well as drive-through lanes. If you are waiting in line for a test make sure you are wearing a mask and maintain a distance of at least 2m from others in the line who are not part of your bubble.

A walk-in testing centre was also set up in the Auckland CBD in the Victoria St carpark near Albert Park this week to make it accessible for the thousands of central city residents without cars.

There is also the option of booking a test through your general practitioner. That way you have a specified time slot, don't need to queue up in a car and should not have to wait so long.